mirror of https://github.com/lammps/lammps.git
git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@665 f3b2605a-c512-4ea7-a41b-209d697bcdaa
This commit is contained in:
parent
c2fc04b265
commit
11ea551f91
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@ -38,6 +38,10 @@ you find errors or omissions in this manual or have suggestions for
|
|||
useful information to add, please send an email to the developers so
|
||||
we can improve the LAMMPS documentation.
|
||||
</P>
|
||||
<P>Once you are familiar with LAMMPS, you may want to bookmark <A HREF = "Section_commands.html#comm">this
|
||||
page</A> at Section_commands.html#comm since
|
||||
it gives quick access to documentation for all LAMMPS commands.
|
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</P>
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<P><A HREF = "Manual.pdf">PDF file</A> of the entire manual, generated by
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<A HREF = "http://www.easysw.com/htmldoc">htmldoc</A>
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</P>
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@ -106,6 +110,12 @@ we can improve the LAMMPS documentation.
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4.10 <A HREF = "Section_howto.html#4_10">Coupling LAMMPS to other codes</A>
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<BR>
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4.11 <A HREF = "Section_howto.html#4_11">Visualizing LAMMPS snapshots</A>
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<BR>
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4.12 <A HREF = "Section_howto.html#4_12">Non-orthogonal simulation boxes</A>
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<BR>
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4.13 <A HREF = "Section_howto.html#4_13">NEMD simulations</A>
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<BR>
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4.14 <A HREF = "Section_howto.html#4_14">Aspherical particles</A>
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<BR></UL>
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<LI><A HREF = "Section_example.html">Example problems</A>
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@ -192,6 +202,12 @@ we can improve the LAMMPS documentation.
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|||
|
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|
|
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@ -35,6 +35,10 @@ you find errors or omissions in this manual or have suggestions for
|
|||
useful information to add, please send an email to the developers so
|
||||
we can improve the LAMMPS documentation.
|
||||
|
||||
Once you are familiar with LAMMPS, you may want to bookmark "this
|
||||
page"_Section_commands.html#comm at Section_commands.html#comm since
|
||||
it gives quick access to documentation for all LAMMPS commands.
|
||||
|
||||
"PDF file"_Manual.pdf of the entire manual, generated by
|
||||
"htmldoc"_http://www.easysw.com/htmldoc
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|
@ -70,7 +74,10 @@ we can improve the LAMMPS documentation.
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|||
4.8 "TIP4P water model"_4_8 :b
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4.9 "SPC water model"_4_9 :b
|
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4.10 "Coupling LAMMPS to other codes"_4_10 :b
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4.11 "Visualizing LAMMPS snapshots"_4_11 :ule,b
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4.11 "Visualizing LAMMPS snapshots"_4_11 :b
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4.12 "Non-orthogonal simulation boxes"_4_12 :b
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4.13 "NEMD simulations"_4_13 :b
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4.14 "Aspherical particles"_4_14 :ule,b
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"Example problems"_Section_example.html :l
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"Performance & scalability"_Section_perf.html :l
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"Additional tools"_Section_tools.html :l
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|
@ -116,6 +123,9 @@ we can improve the LAMMPS documentation.
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|||
:link(4_9,Section_howto.html#4_9)
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:link(4_10,Section_howto.html#4_10)
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:link(4_11,Section_howto.html#4_11)
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:link(4_12,Section_howto.html#4_12)
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:link(4_13,Section_howto.html#4_13)
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:link(4_14,Section_howto.html#4_14)
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:link(9_1,Section_errors.html#9_1)
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:link(9_2,Section_errors.html#9_2)
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|
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@ -345,17 +345,17 @@ for an overview of pair potentials. Click on the style itself for a
|
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full description:
|
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</P>
|
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<DIV ALIGN=center><TABLE WIDTH="0%" BORDER=1 >
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_none.html">none</A></TD><TD ><A HREF = "pair_hybrid.html">hybrid</A></TD><TD ><A HREF = "pair_buck.html">buck</A></TD><TD ><A HREF = "pair_buck.html">buck/coul/cut</A></TD></TR>
|
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<TR ALIGN="center"><TD ><A HREF = "pair_buck.html">buck/coul/long</A></TD><TD ><A HREF = "pair_colloid.html">colloid</A></TD><TD ><A HREF = "pair_dipole/cut.html">dipole/cut</A></TD><TD ><A HREF = "pair_dpd.html">dpd</A></TD></TR>
|
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<TR ALIGN="center"><TD ><A HREF = "pair_eam.html">eam</A></TD><TD ><A HREF = "pair_eam.html">eam/opt</A></TD><TD ><A HREF = "pair_eam.html">eam/alloy</A></TD><TD ><A HREF = "pair_eam.html">eam/alloy/opt</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_eam.html">eam/fs</A></TD><TD ><A HREF = "pair_eam.html">eam/fs/opt</A></TD><TD ><A HREF = "pair_gayberne.html">gayberne</A></TD><TD ><A HREF = "pair_gran.html">gran/hertzian</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_gran.html">gran/history</A></TD><TD ><A HREF = "pair_gran.html">gran/no_history</A></TD><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/charmm</A></TD><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/charmm/implicit</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/long</A></TD><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/long/opt</A></TD><TD ><A HREF = "pair_class2.html">lj/class2</A></TD><TD ><A HREF = "pair_class2.html">lj/class2/coul/cut</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_class2.html">lj/class2/coul/long</A></TD><TD ><A HREF = "pair_lj.html">lj/cut</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/opt</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/coul/cut</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_lj.html">lj/cut/coul/debye</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/coul/long</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/coul/long/tip4p</A></TD><TD ><A HREF = "pair_lj_expand.html">lj/expand</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_lj_smooth.html">lj/smooth</A></TD><TD ><A HREF = "pair_meam.html">meam</A></TD><TD ><A HREF = "pair_morse.html">morse</A></TD><TD ><A HREF = "pair_morse.html">morse/opt</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_soft.html">soft</A></TD><TD ><A HREF = "pair_sw.html">sw</A></TD><TD ><A HREF = "pair_table.html">table</A></TD><TD ><A HREF = "pair_tersoff.html">tersoff</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_yukawa.html">yukawa</A>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_none.html">none</A></TD><TD ><A HREF = "pair_hybrid.html">hybrid</A></TD><TD ><A HREF = "pair_airebo.html">airebo</A></TD><TD ><A HREF = "pair_buck.html">buck</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_buck.html">buck/coul/cut</A></TD><TD ><A HREF = "pair_buck.html">buck/coul/long</A></TD><TD ><A HREF = "pair_colloid.html">colloid</A></TD><TD ><A HREF = "pair_dipole/cut.html">dipole/cut</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_dpd.html">dpd</A></TD><TD ><A HREF = "pair_eam.html">eam</A></TD><TD ><A HREF = "pair_eam.html">eam/opt</A></TD><TD ><A HREF = "pair_eam.html">eam/alloy</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_eam.html">eam/alloy/opt</A></TD><TD ><A HREF = "pair_eam.html">eam/fs</A></TD><TD ><A HREF = "pair_eam.html">eam/fs/opt</A></TD><TD ><A HREF = "pair_gayberne.html">gayberne</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_gran.html">gran/hertzian</A></TD><TD ><A HREF = "pair_gran.html">gran/history</A></TD><TD ><A HREF = "pair_gran.html">gran/no_history</A></TD><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/charmm</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/charmm/implicit</A></TD><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/long</A></TD><TD ><A HREF = "pair_charmm.html">lj/charmm/coul/long/opt</A></TD><TD ><A HREF = "pair_class2.html">lj/class2</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_class2.html">lj/class2/coul/cut</A></TD><TD ><A HREF = "pair_class2.html">lj/class2/coul/long</A></TD><TD ><A HREF = "pair_lj.html">lj/cut</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/opt</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_lj.html">lj/cut/coul/cut</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/coul/debye</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/coul/long</A></TD><TD ><A HREF = "pair_lj.html">lj/cut/coul/long/tip4p</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_lj_expand.html">lj/expand</A></TD><TD ><A HREF = "pair_lj_smooth.html">lj/smooth</A></TD><TD ><A HREF = "pair_meam.html">meam</A></TD><TD ><A HREF = "pair_morse.html">morse</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_morse.html">morse/opt</A></TD><TD ><A HREF = "pair_soft.html">soft</A></TD><TD ><A HREF = "pair_sw.html">sw</A></TD><TD ><A HREF = "pair_table.html">table</A></TD></TR>
|
||||
<TR ALIGN="center"><TD ><A HREF = "pair_tersoff.html">tersoff</A></TD><TD ><A HREF = "pair_yukawa.html">yukawa</A>
|
||||
</TD></TR></TABLE></DIV>
|
||||
|
||||
<HR>
|
||||
|
|
|
@ -459,6 +459,7 @@ full description:
|
|||
|
||||
"none"_pair_none.html,
|
||||
"hybrid"_pair_hybrid.html,
|
||||
"airebo"_pair_airebo.html,
|
||||
"buck"_pair_buck.html,
|
||||
"buck/coul/cut"_pair_buck.html,
|
||||
"buck/coul/long"_pair_buck.html,
|
||||
|
|
|
@ -24,7 +24,10 @@ certain kinds of LAMMPS simulations.
|
|||
4.8 <A HREF = "#4_8">TIP4P water model</A><BR>
|
||||
4.9 <A HREF = "#4_9">SPC water model</A><BR>
|
||||
4.10 <A HREF = "#4_10">Coupling LAMMPS to other codes</A><BR>
|
||||
4.11 <A HREF = "#4_11">Visualizing LAMMPS snapshots</A> <BR>
|
||||
4.11 <A HREF = "#4_11">Visualizing LAMMPS snapshots</A><BR>
|
||||
4.12 <A HREF = "#4_12">Non-orthogonal simulation boxes</A><BR>
|
||||
4.13 <A HREF = "#4_13">NEMD simulations</A><BR>
|
||||
4.14 <A HREF = "#4_14">Aspherical particles</A> <BR>
|
||||
|
||||
<P>The example input scripts included in the LAMMPS distribution and
|
||||
highlighted in <A HREF = "Section_example.html">this section</A> also show how to
|
||||
|
@ -647,6 +650,145 @@ See the <A HREF = "dump.html">dump</A> command for more information on XTC files
|
|||
|
||||
|
||||
|
||||
<HR>
|
||||
|
||||
<A NAME = "4_12"></A><H4>4.12 Non-orthogonal simulation boxes
|
||||
</H4>
|
||||
<P>By default, LAMMPS uses an orthogonal simulation box to encompass the
|
||||
particles. The <A HREF = "boundary.html">boundary</A> command sets the boundary
|
||||
conditions of the box (periodic, non-periodic, etc). If the box size
|
||||
is xprd by yprd by zprd then the 3 mutually orthogonal edge vectors of
|
||||
an orthogonal simulation box are a = (xprd,0,0), b = (0,yprd,0), and c
|
||||
= (0,0,zprd).
|
||||
</P>
|
||||
<P>LAMMPS also allows non-orthogonal simulation boxes (triclinic
|
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symmetry) to be defined with 3 additional "tilt" parameters which
|
||||
change the edge vectors of the simulation box to be a = (xprd,0,0), b
|
||||
= (xy,yprd,0), and c = (xz,yz,zprd). The xy, xz, and yz parameters
|
||||
can be positive or negative. The simulation box must be periodic in
|
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both dimensions associated with a tilt factor. For example, if xz !=
|
||||
0.0, then the x and z dimensions must be periodic.
|
||||
</P>
|
||||
<P>To avoid extremely tilted boxes (which would be computationally
|
||||
inefficient), no tilt factor can skew the box more than half the
|
||||
distance of the parallel box length, which is the 1st dimension in the
|
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tilt factor (x for xz). For example, if xlo = 2 and xhi = 12, then
|
||||
the x box length is 10 and the xy tilt factor must be between -5 and
|
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5. Similarly, both xz and yz must be between -(xhi-xlo)/2 and
|
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+(yhi-ylo)/2. Note that this is not a limitation, since if the
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maximum tilt factor is 5 (as in this example), then configurations
|
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with tilt = ..., -15, -5, 5, 15, 25, ... are all equivalent.
|
||||
</P>
|
||||
<P>You tell LAMMPS to use a non-orthogonal box when the simulation box is
|
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defined. This happens in one of 3 ways. If the
|
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<A HREF = "create_box.html">create_box</A> command is used with a region of style
|
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<I>prism</I>, then a non-orthogonal domain is setup. See the
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<A HREF = "region.html">region</A> command for details. If the
|
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<A HREF = "read_data.html">read_data</A> command is used to define the simulation
|
||||
box, and the header of the data file contains a line with the "xy xz
|
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yz" keyword, then a non-orthogonal domain is setup. See the
|
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<A HREF = "read_data.html">read_data</A> command for details. Finally, if the
|
||||
<A HREF = "read_restart.html">read_restart</A> command reads a restart file which
|
||||
was written from a simulation using a triclinic box, then a
|
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non-orthogonal box will be enabled for the restarted simulation.
|
||||
</P>
|
||||
<P>Note that you can define a non-orthogonal box with all 3 tilt factors
|
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= 0.0, so that it is initially orthogonal. This is necessary if the
|
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box will ever become non-orthogonal.
|
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</P>
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<P>One use of non-orthogonal boxes is to model solid-state crystals with
|
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triclinic symmetry. The <A HREF = "lattice.html">lattice</A> command can be used
|
||||
with non-orthogonal basis vectors to define a lattice that will tile a
|
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non-orthogonal simulation box via the <A HREF = "create_atoms.html">create_atoms</A>
|
||||
command. Note that while the box edge vectors a,b,c cannot be
|
||||
arbitrary vectors (e.g. a must be aligned with the x axis), it is
|
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possible to rotate any crystal's basis vectors so that they meet these
|
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restrictions.
|
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</P>
|
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<P>A second use of non-orthogonal boxes is to shear a bulk solid to study
|
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the response of the material. The <A HREF = "fix_deform.html">fix deform</A>
|
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command can be used for this purpose. It allows dynamic control of
|
||||
the xy, xz, and yz tilt factors as a simulation runs.
|
||||
</P>
|
||||
<P>Another use of non-orthogonal boxes is to perform non-equilibrium MD
|
||||
(NEMD) simulations, as discussed in the next section.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<A NAME = "4_13"></A><H4>4.13 NEMD simulations
|
||||
</H4>
|
||||
<P>Non-equilibrium molecular dynamics or NEMD simulations are typically
|
||||
used to measure a fluid's rheological properties such as viscosity.
|
||||
In LAMMPS, such simulations can be performed by first setting up a
|
||||
non-orthogonal simulation box (see the preceeding Howto section).
|
||||
</P>
|
||||
<P>A shear strain can be applied to the simualation box at a desired
|
||||
strain rate by using the <A HREF = "fix_deform.html">fix deform</A> command. The
|
||||
<A HREF = "fix_nvt_sllod.html">fix nvt/sllod</A> command can be used to thermostat
|
||||
the sheared fluid and integrate the SLLOD equations of motion for the
|
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system. Fix nvt/sllod uses <A HREF = "compute_temp_deform.html">compute
|
||||
temp/deform</A> to compute a thermal temperature
|
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by subtracting out the streaming velocity of the shearing atoms. The
|
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velocity profile or other properties of the fluid can be monitored via
|
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the <A HREF = "fix_ave_spatial.html">fix ave/spatial</A> command.
|
||||
</P>
|
||||
<P>As discussed in the previous section on non-orthogonal simulation
|
||||
boxes, the amount of tilt or skew that can be applied is limited by
|
||||
LAMMPS for computation efficiency to be 1/2 of the paralell box
|
||||
length. However, <A HREF = "fix_deform.html">fix deform</A> can be used to
|
||||
continuously strain a box by an arbitrary amount. As discussed in the
|
||||
<A HREF = "fix_deform.html">fix deform</A> command, when the tilt reaches a limit,
|
||||
the box is re-shaped to the opposite limit which is an equivalent
|
||||
tiling of the periodic plane. The strain rate can then continue to
|
||||
change as before. In a long NEMD simulation these box re-shaping may
|
||||
occur any number of times.
|
||||
</P>
|
||||
<P>In a NEMD simulation, the "remap" option of <A HREF = "fix_deform.html">fix
|
||||
deform</A> should be set to "remap v", since that is what
|
||||
<A HREF = "fix_nvt_sllod.html">fix nvt/sllod</A> assumes to generate a velocity
|
||||
profile consistent with the applied shear strain rate.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<A NAME = "4_14"></A><H4>4.14 Aspherical particles
|
||||
</H4>
|
||||
<P>LAMMPS supports ellipsoidal particles via the <A HREF = "atom_style.html">atom_style
|
||||
ellipsoid</A> and <A HREF = "shape.html">shape</A> commands. The
|
||||
latter defines the 3 axes (diamaters) of a general ellipsoid. The
|
||||
<A HREF = "pair_gayberne.html">pair_style gayberne</A> command can be used to define
|
||||
a Gay-Berne (GB) potential for how such particles interact with each
|
||||
other and with spherical particles. The GB potential is like a
|
||||
Lennard-Jones (LJ) potential generalized for ellipsoids interacting in
|
||||
an orientiation-dependent manner.
|
||||
</P>
|
||||
<P>The orientation of ellipsoidal particles is stored as a quaternion.
|
||||
See the <A HREF = "set.html">set</A> command for a brief explanation of quaternions
|
||||
and how the orientation of such particles can be initialized. The
|
||||
data file read by the <A HREF = "read_data.html">read_data</A> command also contains
|
||||
quaternions for each atom in the Atoms section if <A HREF = "atom_style.html">atom_style
|
||||
ellipsoid</A> is being used. The <A HREF = "compute_temp_asphere.html">compute
|
||||
temp/asphere</A> command can be used to
|
||||
calculate the temperature of a group of ellipsoidal particles, taking
|
||||
account of rotational degrees of freedom. The motion of the particles
|
||||
can be integrated via the <A HREF = "fix_nve_asphere.html">fix nve/asphere</A>, <A HREF = "fix_nvt_asphere.html">fix
|
||||
nvt/asphere</A>, or <A HREF = "fix_npt_asphere.html">fix
|
||||
npt/asphere</A> commands. All of these commands are
|
||||
part of the ASPHERE package in LAMMPS.
|
||||
</P>
|
||||
<P>Computationally, the cost for two ellipsoidal particles to interact is
|
||||
30x or more expensive than for 2 LJ particles. Thus if you are
|
||||
modeling a system with many spherical particles (e.g. as the solvent),
|
||||
then you should insure sphere-sphere interactions are computed with
|
||||
the a cheaper potential than GB. This can be done by setting the
|
||||
particle's 3 shape parameters to all be equal (a sphere).
|
||||
Additionally, the corresponding GB potential coefficients can be set
|
||||
so the GB potential will treat the pair of particles as LJ spheres.
|
||||
Details are given in the doc page for the <A HREF = "pair_gayberne.html">pair_style
|
||||
gayberne</A>. Alternatively, the <A HREF = "pair_hybrid.html">pair_style
|
||||
hybrid</A> potential can be used, with the sphere-sphere
|
||||
interactions computed by another pair potential, such as <A HREF = "pair_lj.html">pair_style
|
||||
lj/cut</A>.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<A NAME = "Cornell"></A>
|
||||
|
|
|
@ -21,7 +21,10 @@ certain kinds of LAMMPS simulations.
|
|||
4.8 "TIP4P water model"_#4_8
|
||||
4.9 "SPC water model"_#4_9
|
||||
4.10 "Coupling LAMMPS to other codes"_#4_10
|
||||
4.11 "Visualizing LAMMPS snapshots"_#4_11 :all(b)
|
||||
4.11 "Visualizing LAMMPS snapshots"_#4_11
|
||||
4.12 "Non-orthogonal simulation boxes"_#4_12
|
||||
4.13 "NEMD simulations"_#4_13
|
||||
4.14 "Aspherical particles"_#4_14 :all(b)
|
||||
|
||||
The example input scripts included in the LAMMPS distribution and
|
||||
highlighted in "this section"_Section_example.html also show how to
|
||||
|
@ -642,6 +645,145 @@ See the "dump"_dump.html command for more information on XTC files.
|
|||
|
||||
:line
|
||||
|
||||
4.12 Non-orthogonal simulation boxes :link(4_12),h4
|
||||
|
||||
By default, LAMMPS uses an orthogonal simulation box to encompass the
|
||||
particles. The "boundary"_boundary.html command sets the boundary
|
||||
conditions of the box (periodic, non-periodic, etc). If the box size
|
||||
is xprd by yprd by zprd then the 3 mutually orthogonal edge vectors of
|
||||
an orthogonal simulation box are a = (xprd,0,0), b = (0,yprd,0), and c
|
||||
= (0,0,zprd).
|
||||
|
||||
LAMMPS also allows non-orthogonal simulation boxes (triclinic
|
||||
symmetry) to be defined with 3 additional "tilt" parameters which
|
||||
change the edge vectors of the simulation box to be a = (xprd,0,0), b
|
||||
= (xy,yprd,0), and c = (xz,yz,zprd). The xy, xz, and yz parameters
|
||||
can be positive or negative. The simulation box must be periodic in
|
||||
both dimensions associated with a tilt factor. For example, if xz !=
|
||||
0.0, then the x and z dimensions must be periodic.
|
||||
|
||||
To avoid extremely tilted boxes (which would be computationally
|
||||
inefficient), no tilt factor can skew the box more than half the
|
||||
distance of the parallel box length, which is the 1st dimension in the
|
||||
tilt factor (x for xz). For example, if xlo = 2 and xhi = 12, then
|
||||
the x box length is 10 and the xy tilt factor must be between -5 and
|
||||
5. Similarly, both xz and yz must be between -(xhi-xlo)/2 and
|
||||
+(yhi-ylo)/2. Note that this is not a limitation, since if the
|
||||
maximum tilt factor is 5 (as in this example), then configurations
|
||||
with tilt = ..., -15, -5, 5, 15, 25, ... are all equivalent.
|
||||
|
||||
You tell LAMMPS to use a non-orthogonal box when the simulation box is
|
||||
defined. This happens in one of 3 ways. If the
|
||||
"create_box"_create_box.html command is used with a region of style
|
||||
{prism}, then a non-orthogonal domain is setup. See the
|
||||
"region"_region.html command for details. If the
|
||||
"read_data"_read_data.html command is used to define the simulation
|
||||
box, and the header of the data file contains a line with the "xy xz
|
||||
yz" keyword, then a non-orthogonal domain is setup. See the
|
||||
"read_data"_read_data.html command for details. Finally, if the
|
||||
"read_restart"_read_restart.html command reads a restart file which
|
||||
was written from a simulation using a triclinic box, then a
|
||||
non-orthogonal box will be enabled for the restarted simulation.
|
||||
|
||||
Note that you can define a non-orthogonal box with all 3 tilt factors
|
||||
= 0.0, so that it is initially orthogonal. This is necessary if the
|
||||
box will ever become non-orthogonal.
|
||||
|
||||
One use of non-orthogonal boxes is to model solid-state crystals with
|
||||
triclinic symmetry. The "lattice"_lattice.html command can be used
|
||||
with non-orthogonal basis vectors to define a lattice that will tile a
|
||||
non-orthogonal simulation box via the "create_atoms"_create_atoms.html
|
||||
command. Note that while the box edge vectors a,b,c cannot be
|
||||
arbitrary vectors (e.g. a must be aligned with the x axis), it is
|
||||
possible to rotate any crystal's basis vectors so that they meet these
|
||||
restrictions.
|
||||
|
||||
A second use of non-orthogonal boxes is to shear a bulk solid to study
|
||||
the response of the material. The "fix deform"_fix_deform.html
|
||||
command can be used for this purpose. It allows dynamic control of
|
||||
the xy, xz, and yz tilt factors as a simulation runs.
|
||||
|
||||
Another use of non-orthogonal boxes is to perform non-equilibrium MD
|
||||
(NEMD) simulations, as discussed in the next section.
|
||||
|
||||
:line
|
||||
|
||||
4.13 NEMD simulations :link(4_13),h4
|
||||
|
||||
Non-equilibrium molecular dynamics or NEMD simulations are typically
|
||||
used to measure a fluid's rheological properties such as viscosity.
|
||||
In LAMMPS, such simulations can be performed by first setting up a
|
||||
non-orthogonal simulation box (see the preceeding Howto section).
|
||||
|
||||
A shear strain can be applied to the simualation box at a desired
|
||||
strain rate by using the "fix deform"_fix_deform.html command. The
|
||||
"fix nvt/sllod"_fix_nvt_sllod.html command can be used to thermostat
|
||||
the sheared fluid and integrate the SLLOD equations of motion for the
|
||||
system. Fix nvt/sllod uses "compute
|
||||
temp/deform"_compute_temp_deform.html to compute a thermal temperature
|
||||
by subtracting out the streaming velocity of the shearing atoms. The
|
||||
velocity profile or other properties of the fluid can be monitored via
|
||||
the "fix ave/spatial"_fix_ave_spatial.html command.
|
||||
|
||||
As discussed in the previous section on non-orthogonal simulation
|
||||
boxes, the amount of tilt or skew that can be applied is limited by
|
||||
LAMMPS for computation efficiency to be 1/2 of the paralell box
|
||||
length. However, "fix deform"_fix_deform.html can be used to
|
||||
continuously strain a box by an arbitrary amount. As discussed in the
|
||||
"fix deform"_fix_deform.html command, when the tilt reaches a limit,
|
||||
the box is re-shaped to the opposite limit which is an equivalent
|
||||
tiling of the periodic plane. The strain rate can then continue to
|
||||
change as before. In a long NEMD simulation these box re-shaping may
|
||||
occur any number of times.
|
||||
|
||||
In a NEMD simulation, the "remap" option of "fix
|
||||
deform"_fix_deform.html should be set to "remap v", since that is what
|
||||
"fix nvt/sllod"_fix_nvt_sllod.html assumes to generate a velocity
|
||||
profile consistent with the applied shear strain rate.
|
||||
|
||||
:line
|
||||
|
||||
4.14 Aspherical particles :link(4_14),h4
|
||||
|
||||
LAMMPS supports ellipsoidal particles via the "atom_style
|
||||
ellipsoid"_atom_style.html and "shape"_shape.html commands. The
|
||||
latter defines the 3 axes (diamaters) of a general ellipsoid. The
|
||||
"pair_style gayberne"_pair_gayberne.html command can be used to define
|
||||
a Gay-Berne (GB) potential for how such particles interact with each
|
||||
other and with spherical particles. The GB potential is like a
|
||||
Lennard-Jones (LJ) potential generalized for ellipsoids interacting in
|
||||
an orientiation-dependent manner.
|
||||
|
||||
The orientation of ellipsoidal particles is stored as a quaternion.
|
||||
See the "set"_set.html command for a brief explanation of quaternions
|
||||
and how the orientation of such particles can be initialized. The
|
||||
data file read by the "read_data"_read_data.html command also contains
|
||||
quaternions for each atom in the Atoms section if "atom_style
|
||||
ellipsoid"_atom_style.html is being used. The "compute
|
||||
temp/asphere"_compute_temp_asphere.html command can be used to
|
||||
calculate the temperature of a group of ellipsoidal particles, taking
|
||||
account of rotational degrees of freedom. The motion of the particles
|
||||
can be integrated via the "fix nve/asphere"_fix_nve_asphere.html, "fix
|
||||
nvt/asphere"_fix_nvt_asphere.html, or "fix
|
||||
npt/asphere"_fix_npt_asphere.html commands. All of these commands are
|
||||
part of the ASPHERE package in LAMMPS.
|
||||
|
||||
Computationally, the cost for two ellipsoidal particles to interact is
|
||||
30x or more expensive than for 2 LJ particles. Thus if you are
|
||||
modeling a system with many spherical particles (e.g. as the solvent),
|
||||
then you should insure sphere-sphere interactions are computed with
|
||||
the a cheaper potential than GB. This can be done by setting the
|
||||
particle's 3 shape parameters to all be equal (a sphere).
|
||||
Additionally, the corresponding GB potential coefficients can be set
|
||||
so the GB potential will treat the pair of particles as LJ spheres.
|
||||
Details are given in the doc page for the "pair_style
|
||||
gayberne"_pair_gayberne.html. Alternatively, the "pair_style
|
||||
hybrid"_pair_hybrid.html potential can be used, with the sphere-sphere
|
||||
interactions computed by another pair potential, such as "pair_style
|
||||
lj/cut"_pair_lj.html.
|
||||
|
||||
:line
|
||||
|
||||
:link(Cornell)
|
||||
[(Cornell)] Cornell, Cieplak, Bayly, Gould, Merz, Ferguson,
|
||||
Spellmeyer, Fox, Caldwell, Kollman, JACS 117, 5179-5197 (1995).
|
||||
|
|
|
@ -128,7 +128,7 @@ commands)
|
|||
<LI> angle potentials: harmonic, CHARMM, cosine, cosine/squared, class 2 (COMPASS)
|
||||
<LI> dihedral potentials: harmonic, CHARMM, multi-harmonic, helix, class 2 (COMPASS), OPLS
|
||||
<LI> improper potentials: harmonic, cvff, class 2 (COMPASS)
|
||||
<LI> hybrid potentials: multiple pair, bond, angle, dihedral, improper potentials can be used
|
||||
<LI> hybrid potentials: multiple pair, bond, angle, dihedral, improper potentials can be used in one simlulation
|
||||
<LI> polymer potentials: all-atom, united-atom, bead-spring, breakable
|
||||
<LI> water potentials: TIP3P, TIP4P, SPC
|
||||
<LI> long-range Coulombics: Ewald, PPPM (similar to particle-mesh Ewald)
|
||||
|
|
|
@ -129,7 +129,7 @@ commands)
|
|||
class 2 (COMPASS), OPLS
|
||||
improper potentials: harmonic, cvff, class 2 (COMPASS)
|
||||
hybrid potentials: multiple pair, bond, angle, dihedral, improper \
|
||||
potentials can be used
|
||||
potentials can be used in one simlulation
|
||||
polymer potentials: all-atom, united-atom, bead-spring, breakable
|
||||
water potentials: TIP3P, TIP4P, SPC
|
||||
long-range Coulombics: Ewald, PPPM (similar to particle-mesh Ewald)
|
||||
|
|
|
@ -46,7 +46,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<P>Theta0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally; hence the units of K are in energy/radian^2.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -43,7 +43,11 @@ r_ub (distance) :ul
|
|||
Theta0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally; hence the units of K are in energy/radian^2.
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -32,8 +32,8 @@ the equilibrium bond lengths.
|
|||
</P>
|
||||
<P>See <A HREF = "#Sun">(Sun)</A> for a description of the COMPASS class2 force field.
|
||||
</P>
|
||||
<P>For this style, only coefficients for the Ea formula can be specified
|
||||
in the input script. These are the 4 coefficients:
|
||||
<P>For this style, coefficients for the Ea formula can be specified in
|
||||
the input script or data file. These are the 4 coefficients:
|
||||
</P>
|
||||
<UL><LI>theta0 (degrees)
|
||||
<LI>K2 (energy/radian^2)
|
||||
|
@ -43,7 +43,7 @@ in the input script. These are the 4 coefficients:
|
|||
<P>Theta0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally; hence the units of K are in energy/radian^2.
|
||||
</P>
|
||||
<P>Coefficients for the Ebb and Eba formulas must be specified in the
|
||||
<P>Coefficients for the Ebb and Eba formulas can only be specified in the
|
||||
data file.
|
||||
</P>
|
||||
<P>For the Ebb formula, the coefficients are listed under a "BondBond
|
||||
|
@ -66,9 +66,9 @@ same value from the Ea formula.
|
|||
</P>
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This angle style is part of the "class2" package. It is only enabled
|
||||
if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>This angle style can only be used if LAMMPS was built with the
|
||||
"class2" package. See the <A HREF = "Section_start.html#2_3">Making LAMMPS</A>
|
||||
section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -29,8 +29,8 @@ the equilibrium bond lengths.
|
|||
|
||||
See "(Sun)"_#Sun for a description of the COMPASS class2 force field.
|
||||
|
||||
For this style, only coefficients for the Ea formula can be specified
|
||||
in the input script. These are the 4 coefficients:
|
||||
For this style, coefficients for the Ea formula can be specified in
|
||||
the input script or data file. These are the 4 coefficients:
|
||||
|
||||
theta0 (degrees)
|
||||
K2 (energy/radian^2)
|
||||
|
@ -40,7 +40,7 @@ K4 (energy/radian^2) :ul
|
|||
Theta0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally; hence the units of K are in energy/radian^2.
|
||||
|
||||
Coefficients for the Ebb and Eba formulas must be specified in the
|
||||
Coefficients for the Ebb and Eba formulas can only be specified in the
|
||||
data file.
|
||||
|
||||
For the Ebb formula, the coefficients are listed under a "BondBond
|
||||
|
@ -63,9 +63,9 @@ same value from the Ea formula.
|
|||
|
||||
[Restrictions:]
|
||||
|
||||
This angle style is part of the "class2" package. It is only enabled
|
||||
if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
This angle style can only be used if LAMMPS was built with the
|
||||
"class2" package. See the "Making LAMMPS"_Section_start.html#2_3
|
||||
section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -35,7 +35,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
</P>
|
||||
<UL><LI>K (energy)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -32,7 +32,11 @@ or "read_restart"_read_restart.html commands:
|
|||
|
||||
K (energy) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -40,7 +40,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<P>Theta0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -37,7 +37,11 @@ theta0 (degrees) :ul
|
|||
Theta0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally.
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -42,6 +42,10 @@ internally; hence the units of K are in energy/radian^2.
|
|||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
</P>
|
||||
<P>This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
<P><A HREF = "angle_coeff.html">angle_coeff</A>
|
||||
|
|
|
@ -39,6 +39,10 @@ internally; hence the units of K are in energy/radian^2.
|
|||
|
||||
[Restrictions:] none
|
||||
|
||||
This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
"angle_coeff"_angle_coeff.html
|
||||
|
|
|
@ -52,7 +52,11 @@ angle type will then be ignored.
|
|||
angle_style hybrid and the corresponding angle_coeff commands, if you
|
||||
desire to turn off certain angle types.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -49,7 +49,11 @@ An angle style of {none} can be specified as an argument to
|
|||
angle_style hybrid and the corresponding angle_coeff commands, if you
|
||||
desire to turn off certain angle types.
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This angle style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -37,14 +37,22 @@ potentials can be setup using the <I>hybrid</I> angle style.
|
|||
<P>The coefficients associated with a angle style can be specified in a
|
||||
data or restart file or via the <A HREF = "angle_coeff.html">angle_coeff</A> command.
|
||||
</P>
|
||||
<P>All angle potentials store their coefficient data in binary restart
|
||||
files which means angle_style and <A HREF = "angle_coeff.html">angle_coeff</A>
|
||||
commands do not need to be re-specified in an input script that
|
||||
restarts a simulation. See the <A HREF = "read_restart.html">read_restart</A>
|
||||
command for details on how to do this. The one exception is that
|
||||
angle_style <I>hybrid</I> only stores the list of sub-styles in the restart
|
||||
file; angle coefficients need to be re-specified.
|
||||
</P>
|
||||
<P>IMPORTANT NOTE: When both an angle and pair style is defined, the
|
||||
<A HREF = "special_bonds.html">special_bonds</A> command often needs to be used to
|
||||
turn off (or weight) the pairwise interaction that would otherwise
|
||||
exist between 3 bonded atoms.
|
||||
</P>
|
||||
<P>In the formulas listed for each angle style, <I>theta</I> is the angle
|
||||
between the 3 atoms in the angle.
|
||||
</P>
|
||||
<P>Note that when both an angle and pair style is defined, the
|
||||
<A HREF = "special_bond.html">special_bond</A> command often needs to be used to
|
||||
turn off (or weight) the pairwise interactions that would otherwise
|
||||
exist between the 3 bonded atoms.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P>Here is an alphabetic list of angle styles defined in LAMMPS. Click on
|
||||
|
@ -67,10 +75,11 @@ specified by the associated <A HREF = "angle_coeff.html">angle_coeff</A> command
|
|||
<P>Angle styles can only be set for atom_styles that allow angles to be
|
||||
defined.
|
||||
</P>
|
||||
<P>Angle styles are part of the "molecular" package or other packages as
|
||||
noted in their documentation. They are only enabled if LAMMPS was
|
||||
built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>Most angle styles are part of the "molecular" package. They are only
|
||||
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages. The
|
||||
doc pages for individual bond potentials tell if it is part of a
|
||||
package.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -35,14 +35,22 @@ potentials can be setup using the {hybrid} angle style.
|
|||
The coefficients associated with a angle style can be specified in a
|
||||
data or restart file or via the "angle_coeff"_angle_coeff.html command.
|
||||
|
||||
All angle potentials store their coefficient data in binary restart
|
||||
files which means angle_style and "angle_coeff"_angle_coeff.html
|
||||
commands do not need to be re-specified in an input script that
|
||||
restarts a simulation. See the "read_restart"_read_restart.html
|
||||
command for details on how to do this. The one exception is that
|
||||
angle_style {hybrid} only stores the list of sub-styles in the restart
|
||||
file; angle coefficients need to be re-specified.
|
||||
|
||||
IMPORTANT NOTE: When both an angle and pair style is defined, the
|
||||
"special_bonds"_special_bonds.html command often needs to be used to
|
||||
turn off (or weight) the pairwise interaction that would otherwise
|
||||
exist between 3 bonded atoms.
|
||||
|
||||
In the formulas listed for each angle style, {theta} is the angle
|
||||
between the 3 atoms in the angle.
|
||||
|
||||
Note that when both an angle and pair style is defined, the
|
||||
"special_bond"_special_bond.html command often needs to be used to
|
||||
turn off (or weight) the pairwise interactions that would otherwise
|
||||
exist between the 3 bonded atoms.
|
||||
|
||||
:line
|
||||
|
||||
Here is an alphabetic list of angle styles defined in LAMMPS. Click on
|
||||
|
@ -65,10 +73,11 @@ specified by the associated "angle_coeff"_angle_coeff.html command:
|
|||
Angle styles can only be set for atom_styles that allow angles to be
|
||||
defined.
|
||||
|
||||
Angle styles are part of the "molecular" package or other packages as
|
||||
noted in their documentation. They are only enabled if LAMMPS was
|
||||
built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
Most angle styles are part of the "molecular" package. They are only
|
||||
enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages. The
|
||||
doc pages for individual bond potentials tell if it is part of a
|
||||
package.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -42,9 +42,9 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
</UL>
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This bond style is part of the "class2" package. It is only enabled
|
||||
if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>This bond style can only be used if LAMMPS was built with the "class2"
|
||||
package. See the <A HREF = "Section_start.html#2_3">Making LAMMPS</A> section for
|
||||
more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -39,9 +39,9 @@ K4 (energy/distance^2) :ul
|
|||
|
||||
[Restrictions:]
|
||||
|
||||
This bond style is part of the "class2" package. It is only enabled
|
||||
if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
This bond style can only be used if LAMMPS was built with the "class2"
|
||||
package. See the "Making LAMMPS"_Section_start.html#2_3 section for
|
||||
more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -42,7 +42,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<LI>epsilon (energy)
|
||||
<LI>sigma (distance)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -39,7 +39,11 @@ R0 (distance)
|
|||
epsilon (energy)
|
||||
sigma (distance) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -47,7 +47,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<LI>sigma (distance)
|
||||
<LI>delta (distance)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -44,7 +44,11 @@ epsilon (energy)
|
|||
sigma (distance)
|
||||
delta (distance) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -37,7 +37,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<UL><LI>K (energy/distance^2)
|
||||
<LI>r0 (distance)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -34,7 +34,11 @@ or "read_restart"_read_restart.html commands:
|
|||
K (energy/distance^2)
|
||||
r0 (distance) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -45,7 +45,11 @@ for K, R0, epsilon, sigma.
|
|||
hybrid and the corresponding bond_coeff commands, if you desire to
|
||||
turn off certain bond types.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -42,7 +42,11 @@ A bond style of {none} can be specified as an argument to bond_style
|
|||
hybrid and the corresponding bond_coeff commands, if you desire to
|
||||
turn off certain bond types.
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -38,7 +38,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<LI>alpha (inverse distance)
|
||||
<LI>r0 (distance)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -35,7 +35,11 @@ D (energy)
|
|||
alpha (inverse distance)
|
||||
r0 (distance) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -38,7 +38,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<LI>r0 (distance)
|
||||
<LI>lamda (distance)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -35,7 +35,11 @@ epsilon (energy)
|
|||
r0 (distance)
|
||||
lamda (distance) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -75,6 +75,10 @@ delete_bonds all bond 0 remove
|
|||
</PRE>
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P>The <I>quartic</I> style requires that <A HREF = "special_bonds.html">special_bonds</A>
|
||||
parameters be set to 1,1,1. Three- and four-body interactions (angle,
|
||||
dihedral, etc) cannot be used with <I>quartic</I> bonds.
|
||||
|
|
|
@ -72,6 +72,10 @@ delete_bonds all bond 0 remove :pre
|
|||
|
||||
[Restrictions:]
|
||||
|
||||
This bond style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
The {quartic} style requires that "special_bonds"_special_bonds.html
|
||||
parameters be set to 1,1,1. Three- and four-body interactions (angle,
|
||||
dihedral, etc) cannot be used with {quartic} bonds.
|
||||
|
|
|
@ -36,9 +36,9 @@ remain in force for the duration of the simulation (unless the bond
|
|||
breaks which is possible in some bond potentials). The list of bonded
|
||||
atoms is read in by a <A HREF = "read_data.html">read_data</A> or
|
||||
<A HREF = "read_restart.html">read_restart</A> command from a data or restart file.
|
||||
By contrast, pair potentials are defined between pairs of atoms that
|
||||
are within a cutoff distance and the set of active interactions
|
||||
typically changes over time.
|
||||
By contrast, pair potentials are typically defined between all pairs
|
||||
of atoms within a cutoff distance and the set of active interactions
|
||||
changes over time.
|
||||
</P>
|
||||
<P>Hybrid models where bonds are computed using different bond potentials
|
||||
can be setup using the <I>hybrid</I> bond style.
|
||||
|
@ -46,14 +46,22 @@ can be setup using the <I>hybrid</I> bond style.
|
|||
<P>The coefficients associated with a bond style can be specified in a
|
||||
data or restart file or via the <A HREF = "bond_coeff.html">bond_coeff</A> command.
|
||||
</P>
|
||||
<P>In the formulas listed for each bond style, <I>r</I> is the distance
|
||||
between the 2 atoms in the bond.
|
||||
<P>All bond potentials store their coefficient data in binary restart
|
||||
files which means bond_style and <A HREF = "bond_coeff.html">bond_coeff</A> commands
|
||||
do not need to be re-specified in an input script that restarts a
|
||||
simulation. See the <A HREF = "read_restart.html">read_restart</A> command for
|
||||
details on how to do this. The one exception is that bond_style
|
||||
<I>hybrid</I> only stores the list of sub-styles in the restart file; bond
|
||||
coefficients need to be re-specified.
|
||||
</P>
|
||||
<P>Note that when both a bond and pair style is defined, the
|
||||
<P>IMPORTANT NOTE: When both a bond and pair style is defined, the
|
||||
<A HREF = "special_bonds.html">special_bonds</A> command often needs to be used to
|
||||
turn off (or weight) the pairwise interaction that would otherwise
|
||||
exist between 2 bonded atoms.
|
||||
</P>
|
||||
<P>In the formulas listed for each bond style, <I>r</I> is the distance
|
||||
between the 2 atoms in the bond.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P>Here is an alphabetic list of bond styles defined in LAMMPS. Click on
|
||||
|
@ -78,10 +86,11 @@ specified by the associated <A HREF = "bond_coeff.html">bond_coeff</A> command:
|
|||
<P>Bond styles can only be set for atom styles that allow bonds to be
|
||||
defined.
|
||||
</P>
|
||||
<P>Bond styles are part of the "molecular" package or other packages as
|
||||
noted in their documentation. They are only enabled if LAMMPS was
|
||||
built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>Most bond styles are part of the "molecular" package. They are only
|
||||
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages. The
|
||||
doc pages for individual bond potentials tell if it is part of a
|
||||
package.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -33,9 +33,9 @@ remain in force for the duration of the simulation (unless the bond
|
|||
breaks which is possible in some bond potentials). The list of bonded
|
||||
atoms is read in by a "read_data"_read_data.html or
|
||||
"read_restart"_read_restart.html command from a data or restart file.
|
||||
By contrast, pair potentials are defined between pairs of atoms that
|
||||
are within a cutoff distance and the set of active interactions
|
||||
typically changes over time.
|
||||
By contrast, pair potentials are typically defined between all pairs
|
||||
of atoms within a cutoff distance and the set of active interactions
|
||||
changes over time.
|
||||
|
||||
Hybrid models where bonds are computed using different bond potentials
|
||||
can be setup using the {hybrid} bond style.
|
||||
|
@ -43,14 +43,22 @@ can be setup using the {hybrid} bond style.
|
|||
The coefficients associated with a bond style can be specified in a
|
||||
data or restart file or via the "bond_coeff"_bond_coeff.html command.
|
||||
|
||||
In the formulas listed for each bond style, {r} is the distance
|
||||
between the 2 atoms in the bond.
|
||||
All bond potentials store their coefficient data in binary restart
|
||||
files which means bond_style and "bond_coeff"_bond_coeff.html commands
|
||||
do not need to be re-specified in an input script that restarts a
|
||||
simulation. See the "read_restart"_read_restart.html command for
|
||||
details on how to do this. The one exception is that bond_style
|
||||
{hybrid} only stores the list of sub-styles in the restart file; bond
|
||||
coefficients need to be re-specified.
|
||||
|
||||
Note that when both a bond and pair style is defined, the
|
||||
IMPORTANT NOTE: When both a bond and pair style is defined, the
|
||||
"special_bonds"_special_bonds.html command often needs to be used to
|
||||
turn off (or weight) the pairwise interaction that would otherwise
|
||||
exist between 2 bonded atoms.
|
||||
|
||||
In the formulas listed for each bond style, {r} is the distance
|
||||
between the 2 atoms in the bond.
|
||||
|
||||
:line
|
||||
|
||||
Here is an alphabetic list of bond styles defined in LAMMPS. Click on
|
||||
|
@ -75,10 +83,11 @@ specified by the associated "bond_coeff"_bond_coeff.html command:
|
|||
Bond styles can only be set for atom styles that allow bonds to be
|
||||
defined.
|
||||
|
||||
Bond styles are part of the "molecular" package or other packages as
|
||||
noted in their documentation. They are only enabled if LAMMPS was
|
||||
built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
Most bond styles are part of the "molecular" package. They are only
|
||||
enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages. The
|
||||
doc pages for individual bond potentials tell if it is part of a
|
||||
package.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -65,7 +65,11 @@ weighting factors (4th coeff above) should be set to 0.0. In this
|
|||
case, you can use any pair style you wish, since the dihedral does not
|
||||
need any 1-4 information.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -62,7 +62,11 @@ weighting factors (4th coeff above) should be set to 0.0. In this
|
|||
case, you can use any pair style you wish, since the dihedral does not
|
||||
need any 1-4 information.
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -35,8 +35,8 @@ bond lengths.
|
|||
</P>
|
||||
<P>See <A HREF = "#Sun">(Sun)</A> for a description of the COMPASS class2 force field.
|
||||
</P>
|
||||
<P>For this style, only coefficients for the Ed formula can be specified
|
||||
in the input script. These are the 6 coefficients:
|
||||
<P>For this style, coefficients for the Ed formula can be specified in
|
||||
either the input script or data file. These are the 6 coefficients:
|
||||
</P>
|
||||
<UL><LI>K1 (energy)
|
||||
<LI>phi1 (degrees)
|
||||
|
@ -45,8 +45,8 @@ in the input script. These are the 6 coefficients:
|
|||
<LI>K3 (energy)
|
||||
<LI>phi3 (degrees)
|
||||
</UL>
|
||||
<P>Coefficients for all the other formulas must be specified in the data
|
||||
file.
|
||||
<P>Coefficients for all the other formulas can only be specified in the
|
||||
data file.
|
||||
</P>
|
||||
<P>For the Embt formula, the coefficients are listed under a
|
||||
"MiddleBondTorsion Coeffs" heading and each line lists 4 coefficients:
|
||||
|
@ -103,9 +103,9 @@ Coeffs" heading and each line lists 3 coefficients:
|
|||
</UL>
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This dihedral style is part of the "class2" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>This dihedral style can only be used if LAMMPS was built with the
|
||||
"class2" package. See the <A HREF = "Section_start.html#2_3">Making LAMMPS</A>
|
||||
section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -32,8 +32,8 @@ bond lengths.
|
|||
|
||||
See "(Sun)"_#Sun for a description of the COMPASS class2 force field.
|
||||
|
||||
For this style, only coefficients for the Ed formula can be specified
|
||||
in the input script. These are the 6 coefficients:
|
||||
For this style, coefficients for the Ed formula can be specified in
|
||||
either the input script or data file. These are the 6 coefficients:
|
||||
|
||||
K1 (energy)
|
||||
phi1 (degrees)
|
||||
|
@ -42,8 +42,8 @@ phi2 (degrees)
|
|||
K3 (energy)
|
||||
phi3 (degrees) :ul
|
||||
|
||||
Coefficients for all the other formulas must be specified in the data
|
||||
file.
|
||||
Coefficients for all the other formulas can only be specified in the
|
||||
data file.
|
||||
|
||||
For the Embt formula, the coefficients are listed under a
|
||||
"MiddleBondTorsion Coeffs" heading and each line lists 4 coefficients:
|
||||
|
@ -100,9 +100,9 @@ r3 (distance) :ul
|
|||
|
||||
[Restrictions:]
|
||||
|
||||
This dihedral style is part of the "class2" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
This dihedral style can only be used if LAMMPS was built with the
|
||||
"class2" package. See the "Making LAMMPS"_Section_start.html#2_3
|
||||
section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -35,7 +35,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<LI>d (+1 or -1)
|
||||
<LI>n (integer >= 0)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -32,7 +32,11 @@ K (energy)
|
|||
d (+1 or -1)
|
||||
n (integer >= 0) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -43,7 +43,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<LI>B (energy)
|
||||
<LI>C (energy)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -40,7 +40,11 @@ A (energy)
|
|||
B (energy)
|
||||
C (energy) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -54,7 +54,11 @@ dihedral type will then be ignored.
|
|||
dihedral_style hybrid and the corresponding dihedral_coeff commands,
|
||||
if you desire to turn off certain dihedral types.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -51,7 +51,11 @@ A dihedral style of {none} can be specified as an argument to
|
|||
dihedral_style hybrid and the corresponding dihedral_coeff commands,
|
||||
if you desire to turn off certain dihedral types.
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -37,7 +37,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<LI>A4 (energy)
|
||||
<LI>A5 (energy)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -34,7 +34,11 @@ A3 (energy)
|
|||
A4 (energy)
|
||||
A5 (energy) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -41,7 +41,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<LI>K3 (energy)
|
||||
<LI>K4 (energy)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -38,7 +38,11 @@ K2 (energy)
|
|||
K3 (energy)
|
||||
K4 (energy) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This dihedral style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -34,17 +34,27 @@ from a data or restart file.
|
|||
<P>Hybrid models where dihedrals are computed using different dihedral
|
||||
potentials can be setup using the <I>hybrid</I> dihedral style.
|
||||
</P>
|
||||
<P>The coefficients associated with a dihedral style can be specified in a
|
||||
data or restart file or via the <A HREF = "dihedral_coeff.html">dihedral_coeff</A> command.
|
||||
<P>The coefficients associated with a dihedral style can be specified in
|
||||
a data or restart file or via the <A HREF = "dihedral_coeff.html">dihedral_coeff</A>
|
||||
command.
|
||||
</P>
|
||||
<P>All dihedral potentials store their coefficient data in binary restart
|
||||
files which means dihedral_style and
|
||||
<A HREF = "dihedral_coeff.html">dihedral_coeff</A> commands do not need to be
|
||||
re-specified in an input script that restarts a simulation. See the
|
||||
<A HREF = "read_restart.html">read_restart</A> command for details on how to do
|
||||
this. The one exception is that dihedral_style <I>hybrid</I> only stores
|
||||
the list of sub-styles in the restart file; dihedral coefficients need
|
||||
to be re-specified.
|
||||
</P>
|
||||
<P>IMPORTANT NOTE: When both a dihedral and pair style is defined, the
|
||||
<A HREF = "special_bonds.html">special_bonds</A> command often needs to be used to
|
||||
turn off (or weight) the pairwise interaction that would otherwise
|
||||
exist between 4 bonded atoms.
|
||||
</P>
|
||||
<P>In the formulas listed for each dihedral style, <I>phi</I> is the torsional
|
||||
angle defined by the quadruplet of atoms.
|
||||
</P>
|
||||
<P>Note that when both a dihedral and pair style is defined, the
|
||||
<A HREF = "special_bond.html">special_bond</A> command often needs to be used to
|
||||
turn off (or weight) the pairwise interactions that would otherwise
|
||||
exist between the 4 bonded atoms.
|
||||
</P>
|
||||
<P>Here are some important points to take note of when defining the
|
||||
LAMMPS dihedral coefficients in the formulas that follow so that they
|
||||
are compatible with other force fields:
|
||||
|
@ -83,10 +93,11 @@ specified by the associated <A HREF = "dihedral_coeff.html">dihedral_coeff</A> c
|
|||
<P>Dihedral styles can only be set for atom styles that allow dihedrals
|
||||
to be defined.
|
||||
</P>
|
||||
<P>Dihedral styles are part of the "molecular" package or other packages
|
||||
as noted in their documentation. They are only enabled if LAMMPS was
|
||||
built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>Most dihedral styles are part of the "molecular" package. They are
|
||||
only enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages. The
|
||||
doc pages for individual dihedral potentials tell if it is part of a
|
||||
package.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -32,17 +32,27 @@ from a data or restart file.
|
|||
Hybrid models where dihedrals are computed using different dihedral
|
||||
potentials can be setup using the {hybrid} dihedral style.
|
||||
|
||||
The coefficients associated with a dihedral style can be specified in a
|
||||
data or restart file or via the "dihedral_coeff"_dihedral_coeff.html command.
|
||||
The coefficients associated with a dihedral style can be specified in
|
||||
a data or restart file or via the "dihedral_coeff"_dihedral_coeff.html
|
||||
command.
|
||||
|
||||
All dihedral potentials store their coefficient data in binary restart
|
||||
files which means dihedral_style and
|
||||
"dihedral_coeff"_dihedral_coeff.html commands do not need to be
|
||||
re-specified in an input script that restarts a simulation. See the
|
||||
"read_restart"_read_restart.html command for details on how to do
|
||||
this. The one exception is that dihedral_style {hybrid} only stores
|
||||
the list of sub-styles in the restart file; dihedral coefficients need
|
||||
to be re-specified.
|
||||
|
||||
IMPORTANT NOTE: When both a dihedral and pair style is defined, the
|
||||
"special_bonds"_special_bonds.html command often needs to be used to
|
||||
turn off (or weight) the pairwise interaction that would otherwise
|
||||
exist between 4 bonded atoms.
|
||||
|
||||
In the formulas listed for each dihedral style, {phi} is the torsional
|
||||
angle defined by the quadruplet of atoms.
|
||||
|
||||
Note that when both a dihedral and pair style is defined, the
|
||||
"special_bond"_special_bond.html command often needs to be used to
|
||||
turn off (or weight) the pairwise interactions that would otherwise
|
||||
exist between the 4 bonded atoms.
|
||||
|
||||
Here are some important points to take note of when defining the
|
||||
LAMMPS dihedral coefficients in the formulas that follow so that they
|
||||
are compatible with other force fields:
|
||||
|
@ -81,10 +91,11 @@ specified by the associated "dihedral_coeff"_dihedral_coeff.html command:
|
|||
Dihedral styles can only be set for atom styles that allow dihedrals
|
||||
to be defined.
|
||||
|
||||
Dihedral styles are part of the "molecular" package or other packages
|
||||
as noted in their documentation. They are only enabled if LAMMPS was
|
||||
built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
Most dihedral styles are part of the "molecular" package. They are
|
||||
only enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages. The
|
||||
doc pages for individual dihedral potentials tell if it is part of a
|
||||
package.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -300,11 +300,11 @@ option - see the <A HREF = "Section_start.html#2_2">Making LAMMPS</A> section of
|
|||
documentation.
|
||||
</P>
|
||||
<P>The <I>bond</I> style is part of the "molecular" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P>The <I>xtc</I> style is part of the "xtc" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info. This is because
|
||||
some machines may not support the lo-level XDR data format that XTC
|
||||
files are written with, which will result in a compile-time error when
|
||||
|
|
|
@ -291,11 +291,11 @@ documentation.
|
|||
|
||||
The {bond} style is part of the "molecular" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
The {xtc} style is part of the "xtc" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info. This is because
|
||||
LAMMPS"_Section_start.html#2_3 section for more info. This is because
|
||||
some machines may not support the lo-level XDR data format that XTC
|
||||
files are written with, which will result in a compile-time error when
|
||||
a lo-level include file is not found. Putting this style in a package
|
||||
|
|
34
doc/fix.html
34
doc/fix.html
|
@ -38,8 +38,7 @@ defined in LAMMPS and new ones can be added - see <A HREF = "Section_modify.html
|
|||
section</A> for a discussion.
|
||||
</P>
|
||||
<P>Each fix style has its own documentation page which describes its
|
||||
arguments and what it does. For example, see the <A HREF = "fix_setforce.html">fix
|
||||
setforce</A> page for information on style <I>setforce</I>.
|
||||
arguments and what it does, as listed below.
|
||||
</P>
|
||||
<P>Fixes perform their operations at different stages of the timestep.
|
||||
If 2 or more fixes both operate at the same stage of the timestep,
|
||||
|
@ -48,10 +47,10 @@ they are invoked in the order they were specified in the input script.
|
|||
<P>Fixes can be deleted with the <A HREF = "unfix.html">unfix</A> command. Note that
|
||||
this is the only way to turn off a fix; simply specifying a new fix
|
||||
with a similar style will not turn off the first one. For example,
|
||||
using a "fix nve" command for a second run after using a "fix nvt"
|
||||
command for the first run, will not cancel out the NVT time
|
||||
integration invoked by the "fix nvt" command. Thus two time
|
||||
integrators would be in place!
|
||||
using a <A HREF = "fix_nve.html">fix nve</A> command for a second run after using a
|
||||
<A HREF = "fix_nvt.html">fix nvt</A> command for the first run, will not cancel out
|
||||
the NVT time integration invoked by the "fix nvt" command. Thus two
|
||||
time integrators would be in place!
|
||||
</P>
|
||||
<P>If you specify a new fix with the same ID and style as an existing
|
||||
fix, the old fix is deleted and the new one is created (presumably
|
||||
|
@ -61,7 +60,18 @@ same order relative to the existing fixes as the old one originally
|
|||
was. Note that this operation also wipes out any additional changes
|
||||
made to the old fix via the <A HREF = "fix_modify.html">fix_modify</A> command.
|
||||
</P>
|
||||
<P>Here is an alphabetic list of fix styles defined in LAMMPS:
|
||||
<P>The <A HREF = "fix_modify.html">fix modify</A> command allows settings for some
|
||||
fixes to be reset. See the doc page for individual fixes for details.
|
||||
</P>
|
||||
<P>Some fixes store an internal "state" which is written to binary
|
||||
restart files via the <A HREF = "restart.html">restart</A> or
|
||||
<A HREF = "write_restart.html">write_restart</A> commands. This allows the fix to
|
||||
continue on with its calculations in a restarted simulation. See the
|
||||
<A HREF = "read_restart.html">read_restart</A> command for info on how to re-specify
|
||||
a fix in an input script that reads a restart file. See the doc pages
|
||||
for individual fixes for info on which ones can be restarted.
|
||||
</P>
|
||||
<P>Here is an alphabetic list of fix styles available in LAMMPS:
|
||||
</P>
|
||||
<UL><LI><A HREF = "fix_addforce.html">fix addforce</A> - add a force to each atom
|
||||
<LI><A HREF = "fix_aveforce.html">fix aveforce</A> - add an averaged force to each atom
|
||||
|
@ -118,13 +128,9 @@ made to the old fix via the <A HREF = "fix_modify.html">fix_modify</A> command.
|
|||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>Some fix styles are part of specific packages. They are only enabled
|
||||
if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P>The <I>freeze</I>, <I>gran/diag</I>, <I>gravity</I>, <I>nve/gran</I>, <I>pour</I>, and
|
||||
<I>wall/gran</I> styles are part of the "granular" package.
|
||||
</P>
|
||||
<P>The <I>poems</I> style is part of the "poems" package.
|
||||
if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages. The
|
||||
doc pages for individual fixes tell if it is part of a package.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
32
doc/fix.txt
32
doc/fix.txt
|
@ -35,8 +35,7 @@ defined in LAMMPS and new ones can be added - see "this
|
|||
section"_Section_modify.html for a discussion.
|
||||
|
||||
Each fix style has its own documentation page which describes its
|
||||
arguments and what it does. For example, see the "fix
|
||||
setforce"_fix_setforce.html page for information on style {setforce}.
|
||||
arguments and what it does, as listed below.
|
||||
|
||||
Fixes perform their operations at different stages of the timestep.
|
||||
If 2 or more fixes both operate at the same stage of the timestep,
|
||||
|
@ -45,10 +44,10 @@ they are invoked in the order they were specified in the input script.
|
|||
Fixes can be deleted with the "unfix"_unfix.html command. Note that
|
||||
this is the only way to turn off a fix; simply specifying a new fix
|
||||
with a similar style will not turn off the first one. For example,
|
||||
using a "fix nve" command for a second run after using a "fix nvt"
|
||||
command for the first run, will not cancel out the NVT time
|
||||
integration invoked by the "fix nvt" command. Thus two time
|
||||
integrators would be in place!
|
||||
using a "fix nve"_fix_nve.html command for a second run after using a
|
||||
"fix nvt"_fix_nvt.html command for the first run, will not cancel out
|
||||
the NVT time integration invoked by the "fix nvt" command. Thus two
|
||||
time integrators would be in place!
|
||||
|
||||
If you specify a new fix with the same ID and style as an existing
|
||||
fix, the old fix is deleted and the new one is created (presumably
|
||||
|
@ -58,7 +57,18 @@ same order relative to the existing fixes as the old one originally
|
|||
was. Note that this operation also wipes out any additional changes
|
||||
made to the old fix via the "fix_modify"_fix_modify.html command.
|
||||
|
||||
Here is an alphabetic list of fix styles defined in LAMMPS:
|
||||
The "fix modify"_fix_modify.html command allows settings for some
|
||||
fixes to be reset. See the doc page for individual fixes for details.
|
||||
|
||||
Some fixes store an internal "state" which is written to binary
|
||||
restart files via the "restart"_restart.html or
|
||||
"write_restart"_write_restart.html commands. This allows the fix to
|
||||
continue on with its calculations in a restarted simulation. See the
|
||||
"read_restart"_read_restart.html command for info on how to re-specify
|
||||
a fix in an input script that reads a restart file. See the doc pages
|
||||
for individual fixes for info on which ones can be restarted.
|
||||
|
||||
Here is an alphabetic list of fix styles available in LAMMPS:
|
||||
|
||||
"fix addforce"_fix_addforce.html - add a force to each atom
|
||||
"fix aveforce"_fix_aveforce.html - add an averaged force to each atom
|
||||
|
@ -124,12 +134,8 @@ Here is an alphabetic list of fix styles defined in LAMMPS:
|
|||
|
||||
Some fix styles are part of specific packages. They are only enabled
|
||||
if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
|
||||
The {freeze}, {gran/diag}, {gravity}, {nve/gran}, {pour}, and
|
||||
{wall/gran} styles are part of the "granular" package.
|
||||
|
||||
The {poems} style is part of the "poems" package.
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages. The
|
||||
doc pages for individual fixes tell if it is part of a package.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -60,7 +60,7 @@
|
|||
<LI>keyword = <I>remap</I> or <I>units</I>
|
||||
|
||||
<PRE> <I>remap</I> value = <I>x</I> or <I>v</I> or <I>none</I>
|
||||
x = remap coords of atoms in group into deforming box (affine deformation)
|
||||
x = remap coords of atoms in group into deforming box
|
||||
v = remap velocities of all atoms when they cross periodic boundaries
|
||||
none = no remapping of x or v
|
||||
<I>units</I> value = <I>lattice</I> or <I>box</I>
|
||||
|
@ -324,18 +324,13 @@ remapped into the new box in the appropriate manner.
|
|||
<P>Each time the box size or shape is changed, the <I>remap</I> keyword
|
||||
determines whether atom positions are re-mapped to the new box. If
|
||||
<I>remap</I> is set to <I>x</I> (the default), atoms in the fix group are
|
||||
re-mapped; otherwise they are not. If all atoms are remapped, this is
|
||||
effectively an "affine" deformation.
|
||||
</P>
|
||||
<P>If <I>remap</I> is set to <I>v</I>, then any atom in the fix group that crosses
|
||||
a periodic boundary will have a delta added to its velocity equal to
|
||||
the difference in velocities between the lo and hi boundaries. Note
|
||||
that this velocity difference can include tilt components, e.g. a
|
||||
delta in the x velocity when an atom crosses the y periodic boundary.
|
||||
If <I>remap</I> is set to <I>none</I>, then neither of these remappings take
|
||||
place. Note that unlike remap x which changes atom coords
|
||||
continuously as the box deforms, this remapping of v is done ONLY when
|
||||
an atom crosses a periodic boundary.
|
||||
re-mapped; otherwise they are not. If <I>remap</I> is set to <I>v</I>, then any
|
||||
atom in the fix group that crosses a periodic boundary will have a
|
||||
delta added to its velocity equal to the difference in velocities
|
||||
between the lo and hi boundaries. Note that this velocity difference
|
||||
can include tilt components, e.g. a delta in the x velocity when an
|
||||
atom crosses the y periodic boundary. If <I>remap</I> is set to <I>none</I>,
|
||||
then neither of these remappings take place.
|
||||
</P>
|
||||
<P>IMPORTANT NOTE: When non-equilibrium MD (NEMD) simulations are
|
||||
performed using this fix, the option "remap v" should normally be
|
||||
|
@ -363,7 +358,9 @@ defined in terms of distance/time.
|
|||
</P>
|
||||
<P>Any box dimension varied by this fix must be periodic.
|
||||
</P>
|
||||
<P><B>Related commands:</B> none
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
<P><A HREF = "displace_box.html">displace_box</A>
|
||||
</P>
|
||||
<P><B>Default:</B>
|
||||
</P>
|
||||
|
|
|
@ -50,7 +50,7 @@ parameter = {x} or {y} or {z} or {xy} or {xz} or {yz}
|
|||
zero or more keyword/value pairs may be appended to the args :l
|
||||
keyword = {remap} or {units} :l
|
||||
{remap} value = {x} or {v} or {none}
|
||||
x = remap coords of atoms in group into deforming box (affine deformation)
|
||||
x = remap coords of atoms in group into deforming box
|
||||
v = remap velocities of all atoms when they cross periodic boundaries
|
||||
none = no remapping of x or v
|
||||
{units} value = {lattice} or {box}
|
||||
|
@ -313,18 +313,13 @@ remapped into the new box in the appropriate manner.
|
|||
Each time the box size or shape is changed, the {remap} keyword
|
||||
determines whether atom positions are re-mapped to the new box. If
|
||||
{remap} is set to {x} (the default), atoms in the fix group are
|
||||
re-mapped; otherwise they are not. If all atoms are remapped, this is
|
||||
effectively an "affine" deformation.
|
||||
|
||||
If {remap} is set to {v}, then any atom in the fix group that crosses
|
||||
a periodic boundary will have a delta added to its velocity equal to
|
||||
the difference in velocities between the lo and hi boundaries. Note
|
||||
that this velocity difference can include tilt components, e.g. a
|
||||
delta in the x velocity when an atom crosses the y periodic boundary.
|
||||
If {remap} is set to {none}, then neither of these remappings take
|
||||
place. Note that unlike remap x which changes atom coords
|
||||
continuously as the box deforms, this remapping of v is done ONLY when
|
||||
an atom crosses a periodic boundary.
|
||||
re-mapped; otherwise they are not. If {remap} is set to {v}, then any
|
||||
atom in the fix group that crosses a periodic boundary will have a
|
||||
delta added to its velocity equal to the difference in velocities
|
||||
between the lo and hi boundaries. Note that this velocity difference
|
||||
can include tilt components, e.g. a delta in the x velocity when an
|
||||
atom crosses the y periodic boundary. If {remap} is set to {none},
|
||||
then neither of these remappings take place.
|
||||
|
||||
IMPORTANT NOTE: When non-equilibrium MD (NEMD) simulations are
|
||||
performed using this fix, the option "remap v" should normally be
|
||||
|
@ -352,7 +347,9 @@ defined in terms of distance/time.
|
|||
|
||||
Any box dimension varied by this fix must be periodic.
|
||||
|
||||
[Related commands:] none
|
||||
[Related commands:]
|
||||
|
||||
"displace_box"_displace_box.html
|
||||
|
||||
[Default:]
|
||||
|
||||
|
|
|
@ -34,33 +34,34 @@ fix_modify 1 energy yes
|
|||
</PRE>
|
||||
<P><B>Description:</B>
|
||||
</P>
|
||||
<P>Modify one or more parameters of a previously defined fix. Not all
|
||||
fix styles support all parameters.
|
||||
<P>Modify one or more parameters of a previously defined fix. Only
|
||||
specific fix styles support specific parameters. See the doc pages
|
||||
for individual fix commands for info on which ones support which
|
||||
fix_modify parameters.
|
||||
</P>
|
||||
<P>The <I>temp</I> keyword is used to determine how a fix computes
|
||||
temperature. The specified compute ID must have been previously
|
||||
defined by the user via the <A HREF = "compute.html">compute</A> command and it must
|
||||
be a style of compute that calculates a temperature. All fixes that
|
||||
compute temperatures defined their own compute by default, as
|
||||
described in their documentation. Thus this option allows the user to
|
||||
override the default method for computing T.
|
||||
compute temperatures define their own compute by default, as described
|
||||
in their documentation. Thus this option allows the user to override
|
||||
the default method for computing T.
|
||||
</P>
|
||||
<P>The <I>press</I> keyword is used to determine how a fix computes pressure.
|
||||
The specified compute ID must have been previously defined by the user
|
||||
via the <A HREF = "compute.html">compute</A> command and it must be a style of
|
||||
compute that calculates a pressure. All fixes that compute pressures
|
||||
defined their own compute by default, as described in their
|
||||
define their own compute by default, as described in their
|
||||
documentation. Thus this option allows the user to override the
|
||||
default method for computing P.
|
||||
</P>
|
||||
<P>For fixes that calculates a contribution to the potential energy of
|
||||
the system, the <I>energy</I> keyword will include that contribution in
|
||||
thermodyanmic output of the potential energy, as invoked by the
|
||||
<A HREF = "thermo_style.html">thermo_style</A> command. The value of the
|
||||
contribution can also be printed by itself using the <A HREF = "thermo_style.html">thermo_style
|
||||
custom</A> keywords. The documentation for individual
|
||||
fix commands specifies whether they make a contribution to the
|
||||
potential energy.
|
||||
<P>For fixes that calculate a contribution to the potential energy of the
|
||||
system, the <I>energy</I> keyword will include that contribution in
|
||||
thermodyanmic output of potential energy. See the
|
||||
<A HREF = "thermo_style.html">thermo_style</A> command for info on how to output
|
||||
potential energy is printed. The contribution itself can also be
|
||||
printed by using the keyword f_ID in the thermo_style custom command,
|
||||
where ID is the fix-ID of the appropriate fix.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
</P>
|
||||
|
|
|
@ -27,33 +27,34 @@ fix_modify 1 energy yes :pre
|
|||
|
||||
[Description:]
|
||||
|
||||
Modify one or more parameters of a previously defined fix. Not all
|
||||
fix styles support all parameters.
|
||||
Modify one or more parameters of a previously defined fix. Only
|
||||
specific fix styles support specific parameters. See the doc pages
|
||||
for individual fix commands for info on which ones support which
|
||||
fix_modify parameters.
|
||||
|
||||
The {temp} keyword is used to determine how a fix computes
|
||||
temperature. The specified compute ID must have been previously
|
||||
defined by the user via the "compute"_compute.html command and it must
|
||||
be a style of compute that calculates a temperature. All fixes that
|
||||
compute temperatures defined their own compute by default, as
|
||||
described in their documentation. Thus this option allows the user to
|
||||
override the default method for computing T.
|
||||
compute temperatures define their own compute by default, as described
|
||||
in their documentation. Thus this option allows the user to override
|
||||
the default method for computing T.
|
||||
|
||||
The {press} keyword is used to determine how a fix computes pressure.
|
||||
The specified compute ID must have been previously defined by the user
|
||||
via the "compute"_compute.html command and it must be a style of
|
||||
compute that calculates a pressure. All fixes that compute pressures
|
||||
defined their own compute by default, as described in their
|
||||
define their own compute by default, as described in their
|
||||
documentation. Thus this option allows the user to override the
|
||||
default method for computing P.
|
||||
|
||||
For fixes that calculates a contribution to the potential energy of
|
||||
the system, the {energy} keyword will include that contribution in
|
||||
thermodyanmic output of the potential energy, as invoked by the
|
||||
"thermo_style"_thermo_style.html command. The value of the
|
||||
contribution can also be printed by itself using the "thermo_style
|
||||
custom"_thermo_style.html keywords. The documentation for individual
|
||||
fix commands specifies whether they make a contribution to the
|
||||
potential energy.
|
||||
For fixes that calculate a contribution to the potential energy of the
|
||||
system, the {energy} keyword will include that contribution in
|
||||
thermodyanmic output of potential energy. See the
|
||||
"thermo_style"_thermo_style.html command for info on how to output
|
||||
potential energy is printed. The contribution itself can also be
|
||||
printed by using the keyword f_ID in the thermo_style custom command,
|
||||
where ID is the fix-ID of the appropriate fix.
|
||||
|
||||
[Restrictions:] none
|
||||
|
||||
|
|
|
@ -39,8 +39,8 @@ equilibrium positions of those angles.
|
|||
the data file or restart files read by the <A HREF = "read_data.html">read_data</A>
|
||||
or <A HREF = "read_restart.html">read_restart</A> commands:
|
||||
</P>
|
||||
<P>For this style, only coefficients for the Ei formula can be specified
|
||||
in the input script. These are the 2 coefficients:
|
||||
<P>For this style, coefficients for the Ei formula can be specified in
|
||||
eiher the input script or data file. These are the 2 coefficients:
|
||||
</P>
|
||||
<UL><LI>K (energy/radian^2)
|
||||
<LI>X0 (degrees)
|
||||
|
@ -48,8 +48,8 @@ in the input script. These are the 2 coefficients:
|
|||
<P>X0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally; hence the units of K are in energy/radian^2.
|
||||
</P>
|
||||
<P>Coefficients for the Eaa formula must be specified in the data file.
|
||||
For the Eaa formula, the coefficients are listed under a
|
||||
<P>Coefficients for the Eaa formula can only be specified in the data
|
||||
file. For the Eaa formula, the coefficients are listed under a
|
||||
"AngleAngle Coeffs" heading and each line lists 6 coefficients:
|
||||
</P>
|
||||
<UL><LI>M1 (energy/distance)
|
||||
|
@ -64,9 +64,9 @@ radians internally; hence the units of M are in energy/radian^2.
|
|||
</P>
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This improper style is part of the "class2" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>This improper style can only be used if LAMMPS was built with the
|
||||
"class2" package. See the <A HREF = "Section_start.html#2_3">Making LAMMPS</A>
|
||||
section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -36,8 +36,8 @@ The following coefficients must be defined for each improper type via the
|
|||
the data file or restart files read by the "read_data"_read_data.html
|
||||
or "read_restart"_read_restart.html commands:
|
||||
|
||||
For this style, only coefficients for the Ei formula can be specified
|
||||
in the input script. These are the 2 coefficients:
|
||||
For this style, coefficients for the Ei formula can be specified in
|
||||
eiher the input script or data file. These are the 2 coefficients:
|
||||
|
||||
K (energy/radian^2)
|
||||
X0 (degrees) :ul
|
||||
|
@ -45,8 +45,8 @@ X0 (degrees) :ul
|
|||
X0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally; hence the units of K are in energy/radian^2.
|
||||
|
||||
Coefficients for the Eaa formula must be specified in the data file.
|
||||
For the Eaa formula, the coefficients are listed under a
|
||||
Coefficients for the Eaa formula can only be specified in the data
|
||||
file. For the Eaa formula, the coefficients are listed under a
|
||||
"AngleAngle Coeffs" heading and each line lists 6 coefficients:
|
||||
|
||||
M1 (energy/distance)
|
||||
|
@ -61,9 +61,9 @@ radians internally; hence the units of M are in energy/radian^2.
|
|||
|
||||
[Restrictions:]
|
||||
|
||||
This improper style is part of the "class2" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
This improper style can only be used if LAMMPS was built with the
|
||||
"class2" package. See the "Making LAMMPS"_Section_start.html#2_3
|
||||
section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -37,7 +37,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<LI>d (+1 or -1)
|
||||
<LI>n (0,1,2,3,4,6)
|
||||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This improper style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -34,7 +34,11 @@ K (energy)
|
|||
d (+1 or -1)
|
||||
n (0,1,2,3,4,6) :ul
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This improper style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -40,7 +40,11 @@ or <A HREF = "read_restart.html">read_restart</A> commands:
|
|||
<P>X0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally; hence the units of K are in energy/radian^2.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This improper style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -37,7 +37,11 @@ X0 (degrees) :ul
|
|||
X0 is specified in degrees, but LAMMPS converts it to radians
|
||||
internally; hence the units of K are in energy/radian^2.
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This improper style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -53,7 +53,11 @@ type will then be ignored.
|
|||
improper_style hybrid and the corresponding improper_coeff commands,
|
||||
if you desire to turn off certain improper types.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This improper style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -50,7 +50,11 @@ An improper style of {none} can be specified as an argument to
|
|||
improper_style hybrid and the corresponding improper_coeff commands,
|
||||
if you desire to turn off certain improper types.
|
||||
|
||||
[Restrictions:] none
|
||||
[Restrictions:]
|
||||
|
||||
This improper style can only be used if LAMMPS was built with the
|
||||
"molecular" package (which it is by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -34,13 +34,23 @@ from a data or restart file.
|
|||
<P>Hybrid models where impropers are computed using different improper
|
||||
potentials can be setup using the <I>hybrid</I> improper style.
|
||||
</P>
|
||||
<P>The coefficients associated with an improper style can be specified in a
|
||||
data or restart file or via the <A HREF = "improper_coeff.html">improper_coeff</A> command.
|
||||
<P>The coefficients associated with an improper style can be specified in
|
||||
a data or restart file or via the <A HREF = "improper_coeff.html">improper_coeff</A>
|
||||
command.
|
||||
</P>
|
||||
<P>Note that when both an improper and pair style is defined, the
|
||||
<A HREF = "special_bond.html">special_bond</A> command often needs to be used to
|
||||
turn off (or weight) the pairwise interactions that would otherwise
|
||||
exist between the 4 bonded atoms.
|
||||
<P>All improper potentials store their coefficient data in binary restart
|
||||
files which means improper_style and
|
||||
<A HREF = "improper_coeff.html">improper_coeff</A> commands do not need to be
|
||||
re-specified in an input script that restarts a simulation. See the
|
||||
<A HREF = "read_restart.html">read_restart</A> command for details on how to do
|
||||
this. The one exception is that improper_style <I>hybrid</I> only stores
|
||||
the list of sub-styles in the restart file; improper coefficients need
|
||||
to be re-specified.
|
||||
</P>
|
||||
<P>IMPORTANT NOTE: When both an improper and pair style is defined, the
|
||||
<A HREF = "special_bonds.html">special_bonds</A> command often needs to be used to
|
||||
turn off (or weight) the pairwise interaction that would otherwise
|
||||
exist between 4 bonded atoms.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
|
@ -62,10 +72,11 @@ specified by the associated <A HREF = "improper_coeff.html">improper_coeff</A> c
|
|||
<P>Improper styles can only be set for atom_style choices that allow
|
||||
impropers to be defined.
|
||||
</P>
|
||||
<P>Improper styles are part of the "molecular" package or other packages
|
||||
as noted in their documentation. They are only enabled if LAMMPS was
|
||||
built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>Most improper styles are part of the "molecular" package. They are
|
||||
only enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info on packages. The
|
||||
doc pages for individual improper potentials tell if it is part of a
|
||||
package.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -31,13 +31,23 @@ from a data or restart file.
|
|||
Hybrid models where impropers are computed using different improper
|
||||
potentials can be setup using the {hybrid} improper style.
|
||||
|
||||
The coefficients associated with an improper style can be specified in a
|
||||
data or restart file or via the "improper_coeff"_improper_coeff.html command.
|
||||
The coefficients associated with an improper style can be specified in
|
||||
a data or restart file or via the "improper_coeff"_improper_coeff.html
|
||||
command.
|
||||
|
||||
Note that when both an improper and pair style is defined, the
|
||||
"special_bond"_special_bond.html command often needs to be used to
|
||||
turn off (or weight) the pairwise interactions that would otherwise
|
||||
exist between the 4 bonded atoms.
|
||||
All improper potentials store their coefficient data in binary restart
|
||||
files which means improper_style and
|
||||
"improper_coeff"_improper_coeff.html commands do not need to be
|
||||
re-specified in an input script that restarts a simulation. See the
|
||||
"read_restart"_read_restart.html command for details on how to do
|
||||
this. The one exception is that improper_style {hybrid} only stores
|
||||
the list of sub-styles in the restart file; improper coefficients need
|
||||
to be re-specified.
|
||||
|
||||
IMPORTANT NOTE: When both an improper and pair style is defined, the
|
||||
"special_bonds"_special_bonds.html command often needs to be used to
|
||||
turn off (or weight) the pairwise interaction that would otherwise
|
||||
exist between 4 bonded atoms.
|
||||
|
||||
:line
|
||||
|
||||
|
@ -59,10 +69,11 @@ specified by the associated "improper_coeff"_improper_coeff.html command:
|
|||
Improper styles can only be set for atom_style choices that allow
|
||||
impropers to be defined.
|
||||
|
||||
Improper styles are part of the "molecular" package or other packages
|
||||
as noted in their documentation. They are only enabled if LAMMPS was
|
||||
built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
Most improper styles are part of the "molecular" package. They are
|
||||
only enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info on packages. The
|
||||
doc pages for individual improper potentials tell if it is part of a
|
||||
package.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -77,7 +77,7 @@ or PPPM solver. The only exception is if the slab option is set with
|
|||
must be periodic and the z dimension must be non-periodic.
|
||||
</P>
|
||||
<P>Kspace styles are part of the "kspace" package. They are only enabled
|
||||
if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P>When using a long-range pairwise TIP4P potential, you must use kspace
|
||||
|
|
|
@ -73,7 +73,7 @@ must be periodic and the z dimension must be non-periodic.
|
|||
|
||||
Kspace styles are part of the "kspace" package. They are only enabled
|
||||
if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
When using a long-range pairwise TIP4P potential, you must use kspace
|
||||
style {pppm/tip4p} and vice versa.
|
||||
|
|
|
@ -86,20 +86,41 @@ Coulombic cutoff cannot be specified for an individual I,J type pair.
|
|||
All type pairs use the same global Coulombic cutoff specified in the
|
||||
pair_style command.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info</B>:
|
||||
</P>
|
||||
<P>None of the Buckingham pair styles support mixing. Thus, coefficients
|
||||
for all I,J pairs must be specified explicitly.
|
||||
</P>
|
||||
<P>All of the Buckingham pair styles support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> shift option for the energy of the
|
||||
exp() and 1/r^6 portion of the pair interaction.
|
||||
</P>
|
||||
<P>The <I>buck/coul/long</I> pair style does not support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> table option since a tabulation
|
||||
capability has not yet been added to this potential.
|
||||
</P>
|
||||
<P>None of the Buckingham pair styles support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> tail option for adding long-range tail
|
||||
corrections to energy and pressure.
|
||||
</P>
|
||||
<P>All of the Buckinham pair styles can calculate per-atom energy and
|
||||
stress, as used by the <A HREF = "compute_epair_atom.html">compute epair/atom</A>,
|
||||
<A HREF = "compute_stress_atom.html">compute stress/atom</A>, and <A HREF = "dump.html">dump
|
||||
custom</A> commands.
|
||||
</P>
|
||||
<P>All of the Buckinham pair styles write their information to <A HREF = "restart.html">binary
|
||||
restart files</A>, so pair_style and pair_coeff commands do
|
||||
not need to be specified in an input script that reads a restart file.
|
||||
</P>
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>The <I>buck</I> potentials do not support the
|
||||
<A HREF = "pair_modify.hmtl">pair_modify</A> <I>mix</I> option. Coefficients for all i,j
|
||||
pairs must be specified explicitly.
|
||||
</P>
|
||||
<P>The <I>buck/coul/long</I> style is part of the "kspace" package. It is
|
||||
only enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P>On some 64-bit machines, compiling with -O3 appears to break the
|
||||
Coulombic tabling option used by the <I>buck/coul/long</I> style. See
|
||||
the "Additional build tips" section of the Making LAMMPS documentation
|
||||
pages for workarounds on this issue.
|
||||
only enabled if LAMMPS was built with that package (which it is by
|
||||
default). See the <A HREF = "Section_start.html#2_3">Making LAMMPS</A> section for
|
||||
more info.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -80,20 +80,41 @@ Coulombic cutoff cannot be specified for an individual I,J type pair.
|
|||
All type pairs use the same global Coulombic cutoff specified in the
|
||||
pair_style command.
|
||||
|
||||
:line
|
||||
|
||||
[Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info]:
|
||||
|
||||
None of the Buckingham pair styles support mixing. Thus, coefficients
|
||||
for all I,J pairs must be specified explicitly.
|
||||
|
||||
All of the Buckingham pair styles support the
|
||||
"pair_modify"_pair_modify.html shift option for the energy of the
|
||||
exp() and 1/r^6 portion of the pair interaction.
|
||||
|
||||
The {buck/coul/long} pair style does not support the
|
||||
"pair_modify"_pair_modify.html table option since a tabulation
|
||||
capability has not yet been added to this potential.
|
||||
|
||||
None of the Buckingham pair styles support the
|
||||
"pair_modify"_pair_modify.html tail option for adding long-range tail
|
||||
corrections to energy and pressure.
|
||||
|
||||
All of the Buckinham pair styles can calculate per-atom energy and
|
||||
stress, as used by the "compute epair/atom"_compute_epair_atom.html,
|
||||
"compute stress/atom"_compute_stress_atom.html, and "dump
|
||||
custom"_dump.html commands.
|
||||
|
||||
All of the Buckinham pair styles write their information to "binary
|
||||
restart files"_restart.html, so pair_style and pair_coeff commands do
|
||||
not need to be specified in an input script that reads a restart file.
|
||||
|
||||
[Restrictions:]
|
||||
|
||||
The {buck} potentials do not support the
|
||||
"pair_modify"_pair_modify.hmtl {mix} option. Coefficients for all i,j
|
||||
pairs must be specified explicitly.
|
||||
|
||||
The {buck/coul/long} style is part of the "kspace" package. It is
|
||||
only enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
|
||||
On some 64-bit machines, compiling with -O3 appears to break the
|
||||
Coulombic tabling option used by the {buck/coul/long} style. See
|
||||
the "Additional build tips" section of the Making LAMMPS documentation
|
||||
pages for workarounds on this issue.
|
||||
only enabled if LAMMPS was built with that package (which it is by
|
||||
default). See the "Making LAMMPS"_Section_start.html#2_3 section for
|
||||
more info.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -95,7 +95,7 @@ faster (for the pairwise portion of the run time).
|
|||
types via the <A HREF = "pair_coeff.html">pair_coeff</A> command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
<A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A>
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
</P>
|
||||
<UL><LI>epsilon (energy units)
|
||||
<LI>sigma (distance units)
|
||||
|
@ -113,12 +113,41 @@ because this CHARMM force field does not allow varying cutoffs for
|
|||
individual atom pairs; all pairs use the global cutoff(s) specified in
|
||||
the pair_style command.
|
||||
</P>
|
||||
<P>If the pair_coeff command is not used to define coefficients for a
|
||||
particular I != J type pair, the mixing rule for epsilon and sigma for
|
||||
all CHARMM potentials is to use the <I>arithmetic</I> formulas documented
|
||||
by the <A HREF = "pair_modify.html">pair_modify</A> command. The <A HREF = "pair_modify.html">pair_modify
|
||||
mix</A> setting is thus ignored for CHARMM potentials.
|
||||
<HR>
|
||||
|
||||
<P><B>Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info</B>:
|
||||
</P>
|
||||
<P>For atom type pairs I,J and I != J, the epsilon, sigma, epsilon_14,
|
||||
and sigma_14 coefficients for all of the lj/charmm pair styles can be
|
||||
mixed. They are always mixed with the value <I>arithmetic</I>. See the
|
||||
"pair_modify" command for details.
|
||||
</P>
|
||||
<P>None of the lj/charmm pair styles support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> shift option, since the Lennard-Jones
|
||||
portion of the pair interaction is smoothed to 0.0 at the cutoff.
|
||||
</P>
|
||||
<P>The <I>lj/charmm/coul/long</I> and <I>lj/charmm/coul/long/opt</I> pair styles
|
||||
support the <A HREF = "pair_modify.html">pair_modify</A> table option since they can
|
||||
tabulate the short-range portion of the long-range Coulombic
|
||||
interaction.
|
||||
</P>
|
||||
<P>None of the lj/charmm pair styles support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> tail option for adding long-range tail
|
||||
corrections to energy and pressure, since the Lennard-Jones portion of
|
||||
the pair interaction is smoothed to 0.0 at the cutoff.
|
||||
</P>
|
||||
<P>All of the lj/charmm pair styles can calculate per-atom energy and
|
||||
stress, as used by the <A HREF = "compute_epair_atom.html">compute epair/atom</A>,
|
||||
<A HREF = "compute_stress_atom.html">compute stress/atom</A>, and <A HREF = "dump.html">dump
|
||||
custom</A> commands.
|
||||
</P>
|
||||
<P>All of the lj/charmm pair styles write their information to <A HREF = "restart.html">binary
|
||||
restart files</A>, so pair_style and pair_coeff commands do
|
||||
not need to be specified in an input script that reads a restart file.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>The <I>lj/charmm/coul/charmm</I> and <I>lj/charmm/coul/charmm/implicit</I>
|
||||
|
@ -126,8 +155,8 @@ styles are part of the "molecule" package. The <I>lj/charmm/coul/long</I>
|
|||
style is part of the "kspace" package. The <I>lj/charmm/coul/long/opt</I>
|
||||
style is part of the "opt" package and also requires the "kspace"
|
||||
package. They are only enabled if LAMMPS was built with those
|
||||
package(s). See the <A HREF = "Section_start.html#2_3">Making LAMMPS</A> section
|
||||
for more info.
|
||||
package(s) (molecule and kspace are by default). See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P>On some 64-bit machines, compiling with -O3 appears to break the
|
||||
Coulombic tabling option used by the <I>lj/charmm/coul/long</I> style. See
|
||||
|
|
|
@ -88,7 +88,7 @@ The following coefficients must be defined for each pair of atoms
|
|||
types via the "pair_coeff"_pair_coeff.html command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
"read_data"_read_data.html or "read_restart"_read_restart.html
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
|
||||
epsilon (energy units)
|
||||
sigma (distance units)
|
||||
|
@ -106,11 +106,40 @@ because this CHARMM force field does not allow varying cutoffs for
|
|||
individual atom pairs; all pairs use the global cutoff(s) specified in
|
||||
the pair_style command.
|
||||
|
||||
If the pair_coeff command is not used to define coefficients for a
|
||||
particular I != J type pair, the mixing rule for epsilon and sigma for
|
||||
all CHARMM potentials is to use the {arithmetic} formulas documented
|
||||
by the "pair_modify"_pair_modify.html command. The "pair_modify
|
||||
mix"_pair_modify.html setting is thus ignored for CHARMM potentials.
|
||||
:line
|
||||
|
||||
[Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info]:
|
||||
|
||||
For atom type pairs I,J and I != J, the epsilon, sigma, epsilon_14,
|
||||
and sigma_14 coefficients for all of the lj/charmm pair styles can be
|
||||
mixed. They are always mixed with the value {arithmetic}. See the
|
||||
"pair_modify" command for details.
|
||||
|
||||
None of the lj/charmm pair styles support the
|
||||
"pair_modify"_pair_modify.html shift option, since the Lennard-Jones
|
||||
portion of the pair interaction is smoothed to 0.0 at the cutoff.
|
||||
|
||||
The {lj/charmm/coul/long} and {lj/charmm/coul/long/opt} pair styles
|
||||
support the "pair_modify"_pair_modify.html table option since they can
|
||||
tabulate the short-range portion of the long-range Coulombic
|
||||
interaction.
|
||||
|
||||
None of the lj/charmm pair styles support the
|
||||
"pair_modify"_pair_modify.html tail option for adding long-range tail
|
||||
corrections to energy and pressure, since the Lennard-Jones portion of
|
||||
the pair interaction is smoothed to 0.0 at the cutoff.
|
||||
|
||||
All of the lj/charmm pair styles can calculate per-atom energy and
|
||||
stress, as used by the "compute epair/atom"_compute_epair_atom.html,
|
||||
"compute stress/atom"_compute_stress_atom.html, and "dump
|
||||
custom"_dump.html commands.
|
||||
|
||||
All of the lj/charmm pair styles write their information to "binary
|
||||
restart files"_restart.html, so pair_style and pair_coeff commands do
|
||||
not need to be specified in an input script that reads a restart file.
|
||||
|
||||
:line
|
||||
|
||||
[Restrictions:]
|
||||
|
||||
|
@ -119,8 +148,8 @@ styles are part of the "molecule" package. The {lj/charmm/coul/long}
|
|||
style is part of the "kspace" package. The {lj/charmm/coul/long/opt}
|
||||
style is part of the "opt" package and also requires the "kspace"
|
||||
package. They are only enabled if LAMMPS was built with those
|
||||
package(s). See the "Making LAMMPS"_Section_start.html#2_3 section
|
||||
for more info.
|
||||
package(s) (molecule and kspace are by default). See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
On some 64-bit machines, compiling with -O3 appears to break the
|
||||
Coulombic tabling option used by the {lj/charmm/coul/long} style. See
|
||||
|
|
|
@ -66,7 +66,7 @@ styles.
|
|||
types via the <A HREF = "pair_coeff.html">pair_coeff</A> command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
<A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A>
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
</P>
|
||||
<UL><LI>epsilon (energy units)
|
||||
<LI>sigma (distance units)
|
||||
|
@ -86,6 +86,8 @@ since a Coulombic cutoff cannot be specified for an individual I,J
|
|||
type pair. All type pairs use the same global Coulombic cutoff
|
||||
specified in the pair_style command.
|
||||
</P>
|
||||
<P>: line
|
||||
</P>
|
||||
<P>If the pair_coeff command is not used to define coefficients for a
|
||||
particular I != J type pair, the mixing rule for epsilon and sigma for
|
||||
all class2 potentials is to use the <I>sixthpower</I> formulas documented
|
||||
|
@ -94,17 +96,44 @@ mix</A> setting is thus ignored for class2 potentials
|
|||
for epsilon and sigma. However it is still followed for mixing the
|
||||
cutoff distance.
|
||||
</P>
|
||||
<P><B>Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info</B>:
|
||||
</P>
|
||||
<P>For atom type pairs I,J and I != J, the epsilon and sigma coefficients
|
||||
and cutoff distance for all of the lj/class2 pair styles can be mixed.
|
||||
Epsilon and sigma are always mixed with the value <I>sixthpower</I>. The
|
||||
cutoff distance is mixed by whatever option is set by the pair_modify
|
||||
command (default = geometric). See the "pair_modify" command for
|
||||
details.
|
||||
</P>
|
||||
<P>All of the lj/class2 pair styles support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> shift option for the energy of the
|
||||
Lennard-Jones portion of the pair interaction.
|
||||
</P>
|
||||
<P>The <I>lj/class2/coul/long</I> pair style does not support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> table option since a tabulation
|
||||
capability has not yet been added to this potential.
|
||||
</P>
|
||||
<P>All of the lj/class2 pair styles support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> tail option for adding a long-range
|
||||
tail correction to the energy and pressure of the Lennard-Jones
|
||||
portion of the pair interaction.
|
||||
</P>
|
||||
<P>All of the lj/class2 pair styles can calculate per-atom energy and
|
||||
stress, as used by the <A HREF = "compute_epair_atom.html">compute epair/atom</A>,
|
||||
<A HREF = "compute_stress_atom.html">compute stress/atom</A>, and <A HREF = "dump.html">dump
|
||||
custom</A> commands.
|
||||
</P>
|
||||
<P>All of the lj/class2 pair styles write their information to <A HREF = "restart.html">binary
|
||||
restart files</A>, so pair_style and pair_coeff commands do
|
||||
not need to be specified in an input script that reads a restart file.
|
||||
</P>
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>These styles are part of the "class2" package. They are only enabled
|
||||
if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
<P>All of these pair styles are part of the "class2" package. They are
|
||||
only enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P>On some 64-bit machines, compiling with -O3 appears to break the
|
||||
Coulombic tabling option used by the <I>lj/class2/coul/long</I> style. See
|
||||
the "Additional build tips" section of the Making LAMMPS documentation
|
||||
pages for workarounds on this issue.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
<P><A HREF = "pair_coeff.html">pair_coeff</A>
|
||||
|
|
|
@ -60,7 +60,7 @@ The following coefficients must be defined for each pair of atoms
|
|||
types via the "pair_coeff"_pair_coeff.html command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
"read_data"_read_data.html or "read_restart"_read_restart.html
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
|
||||
epsilon (energy units)
|
||||
sigma (distance units)
|
||||
|
@ -80,6 +80,8 @@ since a Coulombic cutoff cannot be specified for an individual I,J
|
|||
type pair. All type pairs use the same global Coulombic cutoff
|
||||
specified in the pair_style command.
|
||||
|
||||
: line
|
||||
|
||||
If the pair_coeff command is not used to define coefficients for a
|
||||
particular I != J type pair, the mixing rule for epsilon and sigma for
|
||||
all class2 potentials is to use the {sixthpower} formulas documented
|
||||
|
@ -88,16 +90,43 @@ mix"_pair_modify.html setting is thus ignored for class2 potentials
|
|||
for epsilon and sigma. However it is still followed for mixing the
|
||||
cutoff distance.
|
||||
|
||||
[Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info]:
|
||||
|
||||
For atom type pairs I,J and I != J, the epsilon and sigma coefficients
|
||||
and cutoff distance for all of the lj/class2 pair styles can be mixed.
|
||||
Epsilon and sigma are always mixed with the value {sixthpower}. The
|
||||
cutoff distance is mixed by whatever option is set by the pair_modify
|
||||
command (default = geometric). See the "pair_modify" command for
|
||||
details.
|
||||
|
||||
All of the lj/class2 pair styles support the
|
||||
"pair_modify"_pair_modify.html shift option for the energy of the
|
||||
Lennard-Jones portion of the pair interaction.
|
||||
|
||||
The {lj/class2/coul/long} pair style does not support the
|
||||
"pair_modify"_pair_modify.html table option since a tabulation
|
||||
capability has not yet been added to this potential.
|
||||
|
||||
All of the lj/class2 pair styles support the
|
||||
"pair_modify"_pair_modify.html tail option for adding a long-range
|
||||
tail correction to the energy and pressure of the Lennard-Jones
|
||||
portion of the pair interaction.
|
||||
|
||||
All of the lj/class2 pair styles can calculate per-atom energy and
|
||||
stress, as used by the "compute epair/atom"_compute_epair_atom.html,
|
||||
"compute stress/atom"_compute_stress_atom.html, and "dump
|
||||
custom"_dump.html commands.
|
||||
|
||||
All of the lj/class2 pair styles write their information to "binary
|
||||
restart files"_restart.html, so pair_style and pair_coeff commands do
|
||||
not need to be specified in an input script that reads a restart file.
|
||||
|
||||
[Restrictions:]
|
||||
|
||||
These styles are part of the "class2" package. They are only enabled
|
||||
if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
|
||||
On some 64-bit machines, compiling with -O3 appears to break the
|
||||
Coulombic tabling option used by the {lj/class2/coul/long} style. See
|
||||
the "Additional build tips" section of the Making LAMMPS documentation
|
||||
pages for workarounds on this issue.
|
||||
All of these pair styles are part of the "class2" package. They are
|
||||
only enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -40,7 +40,7 @@ can be used for each, as in the 1st example above. I <= J is
|
|||
required. LAMMPS sets the coefficients for the symmetric J,I
|
||||
interaction to the same values.
|
||||
</P>
|
||||
<P>A wild-card asterik can be used in place of in conjunction with the
|
||||
<P>A wild-card asterik can be used in place of or in conjunction with the
|
||||
I,J arguments to set the coefficients for multiple pairs of atom
|
||||
types. This takes the form "*" or "*n" or "n*" or "m*n". If N = the
|
||||
number of atom types, then an asterik with no numeric values means all
|
||||
|
@ -73,8 +73,9 @@ as
|
|||
<P>For many potentials, if coefficients for type pairs with I != J are
|
||||
not set explicity by a pair_coeff command, the values are inferred
|
||||
from the I,I and J,J settings by mixing rules; see the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> command for a discussion. Exceptions
|
||||
to the mixing rules are discussed with the individual pair styles.
|
||||
<A HREF = "pair_modify.html">pair_modify</A> command for a discussion. Details on
|
||||
this option as it pertains to individual potentials are described on
|
||||
the doc page for the potential.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
|
@ -83,21 +84,15 @@ the style to display the formula it computes, arguments specified in
|
|||
the pair_style command, and coefficients specified by the associated
|
||||
<A HREF = "pair_coeff.html">pair_coeff</A> command:
|
||||
</P>
|
||||
<UL><LI><A HREF = "pair_none.html">pair_style none</A> - turn off pairwise interactions
|
||||
<LI><A HREF = "pair_hybrid.html">pair_style hybrid</A> - define multiple styles of pairwise interactions
|
||||
</UL>
|
||||
<UL><LI><A HREF = "pair_buck.html">pair_style buck</A> - Buckingham potential
|
||||
<UL><LI><A HREF = "pair_airebo.html">pair_style airebo</A> - AI-REBO potential
|
||||
<LI><A HREF = "pair_buck.html">pair_style buck</A> - Buckingham potential
|
||||
<LI><A HREF = "pair_buck.html">pair_style buck/coul/cut</A> - Buckinhham with cutoff Coulomb
|
||||
<LI><A HREF = "pair_buck.html">pair_style buck/coul/long</A> - Buckingham with long-range Coulomb
|
||||
<LI><A HREF = "pair_colloid.html">pair_style colloid</A> - integrated colloidal potential
|
||||
<LI><A HREF = "pair_dpd.html">pair_style dipole/cut</A> - point dipole potential
|
||||
<LI><A HREF = "pair_dpd.html">pair_style dpd</A> - dissipative particle dynamics (DPD)
|
||||
<LI><A HREF = "pair_eam.html">pair_style eam</A> - embedded atom method (EAM)
|
||||
<LI><A HREF = "pair_eam.html">pair_style eam/opt</A> - optimized embedded atom method (EAM)
|
||||
<LI><A HREF = "pair_eam.html">pair_style eam/alloy</A> - alloy EAM
|
||||
<LI><A HREF = "pair_eam.html">pair_style eam/alloy/opt</A> - optimized alloy EAM
|
||||
<LI><A HREF = "pair_eam.html">pair_style eam/fs</A> - Finnis-Sinclair EAM
|
||||
<LI><A HREF = "pair_eam.html">pair_style eam/fs/opt</A> - optimized Finnis-Sinclair EAM
|
||||
<LI><A HREF = "pair_gayberne.html">pair_style gayberne</A> - Gay-Berne ellipsoidal potential
|
||||
<LI><A HREF = "pair_gran.html">pair_style gran/hertzian</A> - granular potential with Hertizain interactions
|
||||
<LI><A HREF = "pair_gran.html">pair_style gran/history</A> - granular potential with history effects
|
||||
|
@ -105,12 +100,10 @@ the pair_style command, and coefficients specified by the associated
|
|||
<LI><A HREF = "pair_charmm.html">pair_style lj/charmm/coul/charmm</A> - CHARMM potential with cutoff Coulomb
|
||||
<LI><A HREF = "pair_charmm.html">pair_style lj/charmm/coul/charmm/implicit</A> - CHARMM for implicit solvent
|
||||
<LI><A HREF = "pair_charmm.html">pair_style lj/charmm/coul/long</A> - CHARMM with long-range Coulomb
|
||||
<LI><A HREF = "pair_charmm.html">pair_style lj/charmm/coul/long/opt</A> - optimized CHARMM with long-range Coulomb
|
||||
<LI><A HREF = "pair_class2.html">pair_style lj/class2</A> - COMPASS (class 2) force field with no Coulomb
|
||||
<LI><A HREF = "pair_class2.html">pair_style lj/class2/coul/cut</A> - COMPASS with cutoff Coulomb
|
||||
<LI><A HREF = "pair_class2.html">pair_style lj/class2/coul/long</A> - COMPASS with long-range Coulomb
|
||||
<LI><A HREF = "pair_lj.html">pair_style lj/cut</A> - cutoff Lennard-Jones potential with no Coulomb
|
||||
<LI><A HREF = "pair_lj.html">pair_style lj/cut/opt</A> - optimized cutoff Lennard-Jones potential with no Coulomb
|
||||
<LI><A HREF = "pair_lj.html">pair_style lj/cut/coul/cut</A> - LJ with cutoff Coulomb
|
||||
<LI><A HREF = "pair_lj.html">pair_style lj/cut/coul/debye</A> - LJ with Debye damping added to Coulomb
|
||||
<LI><A HREF = "pair_lj.html">pair_style lj/cut/coul/long</A> - LJ with long-range Coulomb
|
||||
|
@ -119,7 +112,6 @@ the pair_style command, and coefficients specified by the associated
|
|||
<LI><A HREF = "pair_lj_smooth.html">pair_style lj/smooth</A> - smoothed Lennard-Jones potential
|
||||
<LI><A HREF = "pair_meam.html">pair_style meam</A> - modified embedded atom method (MEAM)
|
||||
<LI><A HREF = "pair_morse.html">pair_style morse</A> - Morse potential
|
||||
<LI><A HREF = "pair_morse.html">pair_style morse/opt</A> - optimized Morse potential
|
||||
<LI><A HREF = "pair_soft.html">pair_style soft</A> - Soft (cosine) potential
|
||||
<LI><A HREF = "pair_sw.html">pair_style sw</A> - Stillinger-Weber 3-body potential
|
||||
<LI><A HREF = "pair_table.html">pair_style table</A> - tabulated pair potential
|
||||
|
|
|
@ -37,7 +37,7 @@ can be used for each, as in the 1st example above. I <= J is
|
|||
required. LAMMPS sets the coefficients for the symmetric J,I
|
||||
interaction to the same values.
|
||||
|
||||
A wild-card asterik can be used in place of in conjunction with the
|
||||
A wild-card asterik can be used in place of or in conjunction with the
|
||||
I,J arguments to set the coefficients for multiple pairs of atom
|
||||
types. This takes the form "*" or "*n" or "n*" or "m*n". If N = the
|
||||
number of atom types, then an asterik with no numeric values means all
|
||||
|
@ -70,8 +70,9 @@ as
|
|||
For many potentials, if coefficients for type pairs with I != J are
|
||||
not set explicity by a pair_coeff command, the values are inferred
|
||||
from the I,I and J,J settings by mixing rules; see the
|
||||
"pair_modify"_pair_modify.html command for a discussion. Exceptions
|
||||
to the mixing rules are discussed with the individual pair styles.
|
||||
"pair_modify"_pair_modify.html command for a discussion. Details on
|
||||
this option as it pertains to individual potentials are described on
|
||||
the doc page for the potential.
|
||||
|
||||
:line
|
||||
|
||||
|
@ -80,20 +81,15 @@ the style to display the formula it computes, arguments specified in
|
|||
the pair_style command, and coefficients specified by the associated
|
||||
"pair_coeff"_pair_coeff.html command:
|
||||
|
||||
"pair_style none"_pair_none.html - turn off pairwise interactions
|
||||
"pair_style hybrid"_pair_hybrid.html - define multiple styles of pairwise interactions :ul
|
||||
"pair_style airebo"_pair_airebo.html - AI-REBO potential
|
||||
"pair_style buck"_pair_buck.html - Buckingham potential
|
||||
"pair_style buck/coul/cut"_pair_buck.html - Buckinhham with cutoff Coulomb
|
||||
"pair_style buck/coul/long"_pair_buck.html - Buckingham with long-range Coulomb
|
||||
"pair_style colloid"_pair_colloid.html - integrated colloidal potential
|
||||
"pair_style dipole/cut"_pair_dpd.html - point dipole potential
|
||||
"pair_style dpd"_pair_dpd.html - dissipative particle dynamics (DPD)
|
||||
"pair_style eam"_pair_eam.html - embedded atom method (EAM)
|
||||
"pair_style eam/opt"_pair_eam.html - optimized embedded atom method (EAM)
|
||||
"pair_style eam/alloy"_pair_eam.html - alloy EAM
|
||||
"pair_style eam/alloy/opt"_pair_eam.html - optimized alloy EAM
|
||||
"pair_style eam/fs"_pair_eam.html - Finnis-Sinclair EAM
|
||||
"pair_style eam/fs/opt"_pair_eam.html - optimized Finnis-Sinclair EAM
|
||||
"pair_style gayberne"_pair_gayberne.html - Gay-Berne ellipsoidal potential
|
||||
"pair_style gran/hertzian"_pair_gran.html - granular potential with Hertizain interactions
|
||||
"pair_style gran/history"_pair_gran.html - granular potential with history effects
|
||||
|
@ -101,12 +97,10 @@ the pair_style command, and coefficients specified by the associated
|
|||
"pair_style lj/charmm/coul/charmm"_pair_charmm.html - CHARMM potential with cutoff Coulomb
|
||||
"pair_style lj/charmm/coul/charmm/implicit"_pair_charmm.html - CHARMM for implicit solvent
|
||||
"pair_style lj/charmm/coul/long"_pair_charmm.html - CHARMM with long-range Coulomb
|
||||
"pair_style lj/charmm/coul/long/opt"_pair_charmm.html - optimized CHARMM with long-range Coulomb
|
||||
"pair_style lj/class2"_pair_class2.html - COMPASS (class 2) force field with no Coulomb
|
||||
"pair_style lj/class2/coul/cut"_pair_class2.html - COMPASS with cutoff Coulomb
|
||||
"pair_style lj/class2/coul/long"_pair_class2.html - COMPASS with long-range Coulomb
|
||||
"pair_style lj/cut"_pair_lj.html - cutoff Lennard-Jones potential with no Coulomb
|
||||
"pair_style lj/cut/opt"_pair_lj.html - optimized cutoff Lennard-Jones potential with no Coulomb
|
||||
"pair_style lj/cut/coul/cut"_pair_lj.html - LJ with cutoff Coulomb
|
||||
"pair_style lj/cut/coul/debye"_pair_lj.html - LJ with Debye damping added to Coulomb
|
||||
"pair_style lj/cut/coul/long"_pair_lj.html - LJ with long-range Coulomb
|
||||
|
@ -115,7 +109,6 @@ the pair_style command, and coefficients specified by the associated
|
|||
"pair_style lj/smooth"_pair_lj_smooth.html - smoothed Lennard-Jones potential
|
||||
"pair_style meam"_pair_meam.html - modified embedded atom method (MEAM)
|
||||
"pair_style morse"_pair_morse.html - Morse potential
|
||||
"pair_style morse/opt"_pair_morse.html - optimized Morse potential
|
||||
"pair_style soft"_pair_soft.html - Soft (cosine) potential
|
||||
"pair_style sw"_pair_sw.html - Stillinger-Weber 3-body potential
|
||||
"pair_style table"_pair_table.html - tabulated pair potential
|
||||
|
|
|
@ -62,7 +62,7 @@ Lennard-Jones formula
|
|||
types via the <A HREF = "pair_coeff.html">pair_coeff</A> command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
<A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A>
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
</P>
|
||||
<UL><LI>A (energy units)
|
||||
<LI>sigma (distance units)
|
||||
|
@ -110,16 +110,42 @@ rule-of-thumb is to use a colloid-solvent cutoff that is half the big
|
|||
diamter + 4 times the small diamter. I.e. 9 = 5 + 4 for the
|
||||
colloid-solvent cutoff in this case.
|
||||
</P>
|
||||
<P>If a pair_coeff command is not specified for I != J, then the
|
||||
coefficients are mixed according the mixing rules defined by the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> command. The prefactor A is mixed like
|
||||
the Lennard-Jones epsilon; sigma,d1,d2 are all mixed like the
|
||||
Lennard-Jones sigma.
|
||||
<HR>
|
||||
|
||||
<P><B>Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info</B>:
|
||||
</P>
|
||||
<P>For atom type pairs I,J and I != J, the A, sigma, d1, and d2
|
||||
coefficients and cutoff distance for this pair style can be mixed. A
|
||||
is an energy value mixed like a LJ epsilon. D1 and d2 are distance
|
||||
values and are mixed like sigma. The default mix value is
|
||||
<I>geometric</I>. See the "pair_modify" command for details.
|
||||
</P>
|
||||
<P>This pair style supports the <A HREF = "pair_modify.html">pair_modify</A> shift
|
||||
option for the energy of the pair interaction.
|
||||
</P>
|
||||
<P>The <A HREF = "pair_modify.html">pair_modify</A> table option is not relevant
|
||||
for this pair style.
|
||||
</P>
|
||||
<P>This pair style does not support the <A HREF = "pair_modify.html">pair_modify</A>
|
||||
tail option for adding long-range tail corrections to energy and
|
||||
pressure.
|
||||
</P>
|
||||
<P>This pair style can calculate per-atom energy and stress, as used by
|
||||
the <A HREF = "compute_epair_atom.html">compute epair/atom</A>, <A HREF = "compute_stress_atom.html">compute
|
||||
stress/atom</A>, and <A HREF = "dump.html">dump custom</A>
|
||||
commands.
|
||||
</P>
|
||||
<P>This pair style writes its information to <A HREF = "restart.html">binary restart
|
||||
files</A>, so pair_style and pair_coeff commands do not need
|
||||
to be specified in an input script that reads a restart file.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>The <I>colloid</I> style is part of the "colloid" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
<P>This style is part of the "colloid" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
|
|
|
@ -59,7 +59,7 @@ The following coefficients must be defined for each pair of atoms
|
|||
types via the "pair_coeff"_pair_coeff.html command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
"read_data"_read_data.html or "read_restart"_read_restart.html
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
|
||||
A (energy units)
|
||||
sigma (distance units)
|
||||
|
@ -107,16 +107,42 @@ rule-of-thumb is to use a colloid-solvent cutoff that is half the big
|
|||
diamter + 4 times the small diamter. I.e. 9 = 5 + 4 for the
|
||||
colloid-solvent cutoff in this case.
|
||||
|
||||
If a pair_coeff command is not specified for I != J, then the
|
||||
coefficients are mixed according the mixing rules defined by the
|
||||
"pair_modify"_pair_modify.html command. The prefactor A is mixed like
|
||||
the Lennard-Jones epsilon; sigma,d1,d2 are all mixed like the
|
||||
Lennard-Jones sigma.
|
||||
:line
|
||||
|
||||
[Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info]:
|
||||
|
||||
For atom type pairs I,J and I != J, the A, sigma, d1, and d2
|
||||
coefficients and cutoff distance for this pair style can be mixed. A
|
||||
is an energy value mixed like a LJ epsilon. D1 and d2 are distance
|
||||
values and are mixed like sigma. The default mix value is
|
||||
{geometric}. See the "pair_modify" command for details.
|
||||
|
||||
This pair style supports the "pair_modify"_pair_modify.html shift
|
||||
option for the energy of the pair interaction.
|
||||
|
||||
The "pair_modify"_pair_modify.html table option is not relevant
|
||||
for this pair style.
|
||||
|
||||
This pair style does not support the "pair_modify"_pair_modify.html
|
||||
tail option for adding long-range tail corrections to energy and
|
||||
pressure.
|
||||
|
||||
This pair style can calculate per-atom energy and stress, as used by
|
||||
the "compute epair/atom"_compute_epair_atom.html, "compute
|
||||
stress/atom"_compute_stress_atom.html, and "dump custom"_dump.html
|
||||
commands.
|
||||
|
||||
This pair style writes its information to "binary restart
|
||||
files"_restart.html, so pair_style and pair_coeff commands do not need
|
||||
to be specified in an input script that reads a restart file.
|
||||
|
||||
:line
|
||||
|
||||
[Restrictions:]
|
||||
|
||||
The {colloid} style is part of the "colloid" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the "Making
|
||||
This style is part of the "colloid" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
[Related commands:]
|
||||
|
|
|
@ -62,7 +62,7 @@ dipole</A> command or in the "Atoms" section of the data file.
|
|||
types via the <A HREF = "pair_coeff.html">pair_coeff</A> command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
<A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A>
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
</P>
|
||||
<UL><LI>epsilon (energy units)
|
||||
<LI>sigma (distance units)
|
||||
|
@ -76,12 +76,46 @@ and Coulombic interactions for this type pair. If both coefficients
|
|||
are specified, they are used as the LJ and Coulombic cutoffs for this
|
||||
type pair.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info</B>:
|
||||
</P>
|
||||
<P>For atom type pairs I,J and I != J, the epsilon and sigma coefficients
|
||||
and cutoff distances for this pair style can be mixed. The default
|
||||
mix value is <I>geometric</I>. See the "pair_modify" command for details.
|
||||
</P>
|
||||
<P>For atom type pairs I,J and I != J, the A, sigma, d1, and d2
|
||||
coefficients and cutoff distance for this pair style can be mixed. A
|
||||
is an energy value mixed like a LJ epsilon. D1 and d2 are distance
|
||||
values and are mixed like sigma. The default mix value is
|
||||
<I>geometric</I>. See the "pair_modify" command for details.
|
||||
</P>
|
||||
<P>This pair style supports the <A HREF = "pair_modify.html">pair_modify</A> shift
|
||||
option for the energy of the Lennard-Jones portion of the pair
|
||||
interaction.
|
||||
</P>
|
||||
<P>The <A HREF = "pair_modify.html">pair_modify</A> table option is not relevant
|
||||
for this pair style.
|
||||
</P>
|
||||
<P>This pair style does not support the <A HREF = "pair_modify.html">pair_modify</A>
|
||||
tail option for adding long-range tail corrections to energy and
|
||||
pressure.
|
||||
</P>
|
||||
<P>This pair style can calculate per-atom energy and stress, as used by
|
||||
the <A HREF = "compute_epair_atom.html">compute epair/atom</A>, <A HREF = "compute_stress_atom.html">compute
|
||||
stress/atom</A>, and <A HREF = "dump.html">dump custom</A>
|
||||
commands.
|
||||
</P>
|
||||
<P>This pair style writes its information to <A HREF = "restart.html">binary restart
|
||||
files</A>, so pair_style and pair_coeff commands do not need
|
||||
to be specified in an input script that reads a restart file.
|
||||
</P>
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>Can only be used if LAMMPS was built with the "dipole" package.
|
||||
</P>
|
||||
<P>The use of this potential requires additional fixes as described
|
||||
above.
|
||||
<P>This style is part of the "dipole" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -59,7 +59,7 @@ The following coefficients must be defined for each pair of atoms
|
|||
types via the "pair_coeff"_pair_coeff.html command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
"read_data"_read_data.html or "read_restart"_read_restart.html
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
|
||||
epsilon (energy units)
|
||||
sigma (distance units)
|
||||
|
@ -73,12 +73,46 @@ and Coulombic interactions for this type pair. If both coefficients
|
|||
are specified, they are used as the LJ and Coulombic cutoffs for this
|
||||
type pair.
|
||||
|
||||
:line
|
||||
|
||||
[Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info]:
|
||||
|
||||
For atom type pairs I,J and I != J, the epsilon and sigma coefficients
|
||||
and cutoff distances for this pair style can be mixed. The default
|
||||
mix value is {geometric}. See the "pair_modify" command for details.
|
||||
|
||||
For atom type pairs I,J and I != J, the A, sigma, d1, and d2
|
||||
coefficients and cutoff distance for this pair style can be mixed. A
|
||||
is an energy value mixed like a LJ epsilon. D1 and d2 are distance
|
||||
values and are mixed like sigma. The default mix value is
|
||||
{geometric}. See the "pair_modify" command for details.
|
||||
|
||||
This pair style supports the "pair_modify"_pair_modify.html shift
|
||||
option for the energy of the Lennard-Jones portion of the pair
|
||||
interaction.
|
||||
|
||||
The "pair_modify"_pair_modify.html table option is not relevant
|
||||
for this pair style.
|
||||
|
||||
This pair style does not support the "pair_modify"_pair_modify.html
|
||||
tail option for adding long-range tail corrections to energy and
|
||||
pressure.
|
||||
|
||||
This pair style can calculate per-atom energy and stress, as used by
|
||||
the "compute epair/atom"_compute_epair_atom.html, "compute
|
||||
stress/atom"_compute_stress_atom.html, and "dump custom"_dump.html
|
||||
commands.
|
||||
|
||||
This pair style writes its information to "binary restart
|
||||
files"_restart.html, so pair_style and pair_coeff commands do not need
|
||||
to be specified in an input script that reads a restart file.
|
||||
|
||||
[Restrictions:]
|
||||
|
||||
Can only be used if LAMMPS was built with the "dipole" package.
|
||||
|
||||
The use of this potential requires additional fixes as described
|
||||
above.
|
||||
This style is part of the "dipole" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -56,16 +56,49 @@ cutoff is used. Note that sigma is set equal to sqrt(2 T gamma),
|
|||
where T is the temperature set by the <A HREF = "pair_style.html">pair_style</A>
|
||||
command so it does not need to be specified.
|
||||
</P>
|
||||
<P><B>Restrictions:</B> none
|
||||
<HR>
|
||||
|
||||
<P><B>Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info</B>:
|
||||
</P>
|
||||
<P>This style is part of the "dpd" package. It is only enabled if LAMMPS
|
||||
was built with those package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
<P>Thsi pair style does not support mixing. Thus, coefficients for all
|
||||
I,J pairs must be specified explicitly.
|
||||
</P>
|
||||
<P>This pair style does not support the <A HREF = "pair_modify.html">pair_modify</A>
|
||||
shift option for the energy of the pair interaction.
|
||||
</P>
|
||||
<P>The <A HREF = "pair_modify.html">pair_modify</A> table option is not relevant
|
||||
for this pair style.
|
||||
</P>
|
||||
<P>This pair style does not support the <A HREF = "pair_modify.html">pair_modify</A>
|
||||
tail option for adding long-range tail corrections to energy and
|
||||
pressure.
|
||||
</P>
|
||||
<P>This pair style can calculate per-atom energy and stress, as used by
|
||||
the <A HREF = "compute_epair_atom.html">compute epair/atom</A>, <A HREF = "compute_stress_atom.html">compute
|
||||
stress/atom</A>, and <A HREF = "dump.html">dump custom</A>
|
||||
commands. However, only the first term with the A coefficienct
|
||||
(conservative force) is used for these computations. The drag force
|
||||
and random force terms are not.
|
||||
</P>
|
||||
<P>This pair style writes its information to <A HREF = "restart.html">binary restart
|
||||
files</A>, so pair_style and pair_coeff commands do not need
|
||||
to be specified in an input script that reads a restart file. Note
|
||||
that the user-specifice random number seed is stored in the restart
|
||||
file, so when a simulation is restarted, each processor will
|
||||
re-initialize its random number generator the same way it did
|
||||
intially. This means the random forces will be random, but will not
|
||||
be the same as they would have been if the original simulation had
|
||||
continued past the restart time.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>This style is part of the "dpd" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P>The <I>dpd</I> potential does not support the
|
||||
<A HREF = "pair_modify.hmtl">pair_modify</A> <I>mix</I> option. Coefficients for all i,j
|
||||
pairs must be specified explicitly.
|
||||
</P>
|
||||
<P>The default frequency for rebuilding neighbor lists is every 10 steps
|
||||
(see the <A HREF = "neigh_modify.html">neigh_modify</A> command). This may be too
|
||||
infrequent for DPD simulations since particles move rapidly and can
|
||||
|
|
|
@ -53,15 +53,48 @@ cutoff is used. Note that sigma is set equal to sqrt(2 T gamma),
|
|||
where T is the temperature set by the "pair_style"_pair_style.html
|
||||
command so it does not need to be specified.
|
||||
|
||||
[Restrictions:] none
|
||||
:line
|
||||
|
||||
This style is part of the "dpd" package. It is only enabled if LAMMPS
|
||||
was built with those package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
[Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info]:
|
||||
|
||||
The {dpd} potential does not support the
|
||||
"pair_modify"_pair_modify.hmtl {mix} option. Coefficients for all i,j
|
||||
pairs must be specified explicitly.
|
||||
Thsi pair style does not support mixing. Thus, coefficients for all
|
||||
I,J pairs must be specified explicitly.
|
||||
|
||||
This pair style does not support the "pair_modify"_pair_modify.html
|
||||
shift option for the energy of the pair interaction.
|
||||
|
||||
The "pair_modify"_pair_modify.html table option is not relevant
|
||||
for this pair style.
|
||||
|
||||
This pair style does not support the "pair_modify"_pair_modify.html
|
||||
tail option for adding long-range tail corrections to energy and
|
||||
pressure.
|
||||
|
||||
This pair style can calculate per-atom energy and stress, as used by
|
||||
the "compute epair/atom"_compute_epair_atom.html, "compute
|
||||
stress/atom"_compute_stress_atom.html, and "dump custom"_dump.html
|
||||
commands. However, only the first term with the A coefficienct
|
||||
(conservative force) is used for these computations. The drag force
|
||||
and random force terms are not.
|
||||
|
||||
This pair style writes its information to "binary restart
|
||||
files"_restart.html, so pair_style and pair_coeff commands do not need
|
||||
to be specified in an input script that reads a restart file. Note
|
||||
that the user-specifice random number seed is stored in the restart
|
||||
file, so when a simulation is restarted, each processor will
|
||||
re-initialize its random number generator the same way it did
|
||||
intially. This means the random forces will be random, but will not
|
||||
be the same as they would have been if the original simulation had
|
||||
continued past the restart time.
|
||||
|
||||
:line
|
||||
|
||||
[Restrictions:]
|
||||
|
||||
This style is part of the "dpd" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
The default frequency for rebuilding neighbor lists is every 10 steps
|
||||
(see the "neigh_modify"_neigh_modify.html command). This may be too
|
||||
|
|
|
@ -322,11 +322,46 @@ are listed.
|
|||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info</B>:
|
||||
</P>
|
||||
<P>For atom type pairs I,J and I != J, mixing is performed by LAMMPS as
|
||||
described above with the individual styles. You never need to specify
|
||||
a pair_coeff command with I != J arguments for the eam styles.
|
||||
</P>
|
||||
<P>This pair style does not support the <A HREF = "pair_modify.html">pair_modify</A>
|
||||
shift option for the energy of the pair interaction.
|
||||
</P>
|
||||
<P>The <A HREF = "pair_modify.html">pair_modify</A> shift option is not relevant
|
||||
for this pair style.
|
||||
</P>
|
||||
<P>The <A HREF = "pair_modify.html">pair_modify</A> table option is not relevant
|
||||
for this pair style.
|
||||
</P>
|
||||
<P>The <A HREF = "pair_modify.html">pair_modify</A> tail option is not relevant
|
||||
for this pair style.
|
||||
</P>
|
||||
<P>All of the eam pair styles can calculate per-atom energy and stress,
|
||||
as used by the <A HREF = "compute_epair_atom.html">compute epair/atom</A>, <A HREF = "compute_stress_atom.html">compute
|
||||
stress/atom</A>, and <A HREF = "dump.html">dump custom</A>
|
||||
commands. These quantities include the contribution from the
|
||||
embedding term in the EAM formulas.
|
||||
</P>
|
||||
<P>None of the eam pair styles write their information to <A HREF = "restart.html">binary restart
|
||||
files</A>, since the info is tabulated in potential files.
|
||||
Thus, you need to re-specify the pair style and coefficient commands
|
||||
in an input script that reads a restart file.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>The <I>opt</I> styles are part of the "opt" package. They are only enabled
|
||||
if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>All of these styles except those ending in <I>opt</I> are part of the
|
||||
"manybody" package. They are only enabled if LAMMPS was built with
|
||||
that package (which it is by default). The styles ending in <I>opt</I> are
|
||||
part of the "opt" package and also require the "manybody" package.
|
||||
They are only enabled if LAMMPS was built with those packages. See
|
||||
the <A HREF = "Section_start.html#2_3">Making LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -314,11 +314,46 @@ are listed.
|
|||
|
||||
:line
|
||||
|
||||
[Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info]:
|
||||
|
||||
For atom type pairs I,J and I != J, mixing is performed by LAMMPS as
|
||||
described above with the individual styles. You never need to specify
|
||||
a pair_coeff command with I != J arguments for the eam styles.
|
||||
|
||||
This pair style does not support the "pair_modify"_pair_modify.html
|
||||
shift option for the energy of the pair interaction.
|
||||
|
||||
The "pair_modify"_pair_modify.html shift option is not relevant
|
||||
for this pair style.
|
||||
|
||||
The "pair_modify"_pair_modify.html table option is not relevant
|
||||
for this pair style.
|
||||
|
||||
The "pair_modify"_pair_modify.html tail option is not relevant
|
||||
for this pair style.
|
||||
|
||||
All of the eam pair styles can calculate per-atom energy and stress,
|
||||
as used by the "compute epair/atom"_compute_epair_atom.html, "compute
|
||||
stress/atom"_compute_stress_atom.html, and "dump custom"_dump.html
|
||||
commands. These quantities include the contribution from the
|
||||
embedding term in the EAM formulas.
|
||||
|
||||
None of the eam pair styles write their information to "binary restart
|
||||
files"_restart.html, since the info is tabulated in potential files.
|
||||
Thus, you need to re-specify the pair style and coefficient commands
|
||||
in an input script that reads a restart file.
|
||||
|
||||
:line
|
||||
|
||||
[Restrictions:]
|
||||
|
||||
The {opt} styles are part of the "opt" package. They are only enabled
|
||||
if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
All of these styles except those ending in {opt} are part of the
|
||||
"manybody" package. They are only enabled if LAMMPS was built with
|
||||
that package (which it is by default). The styles ending in {opt} are
|
||||
part of the "opt" package and also require the "manybody" package.
|
||||
They are only enabled if LAMMPS was built with those packages. See
|
||||
the "Making LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -82,10 +82,6 @@ commands:
|
|||
<P>The last coefficient is optional. If not specified, the global
|
||||
cutoff specified in the pair_style command is used.
|
||||
</P>
|
||||
<P>The epsilon and sigma parameters are mixed for I != J atom pairings
|
||||
the same as Lennard-Jones parameters; see the <A HREF = "pair_modify.html">pair_modify
|
||||
mix</A> documentation for details.
|
||||
</P>
|
||||
<P>The epsilon_i and epsilon_j coefficients are actually defined for atom
|
||||
types, not for pairs of atom types. Thus, in a series of pair_coeff
|
||||
commands, they only need to be specified once for each atom type.
|
||||
|
@ -119,17 +115,49 @@ than the full Gay-Berne formula. Thus you should insure epsilon a,b,c
|
|||
are set to 1.0 for spherical particle types and use epsilon and sigma
|
||||
to specify its interaction with other spherical particles.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info</B>:
|
||||
</P>
|
||||
<P>For atom type pairs I,J and I != J, the epsilon and sigma coefficients
|
||||
and cutoff distance for this pair style can be mixed. The default mix
|
||||
value is <I>geometric</I>. See the "pair_modify" command for details.
|
||||
</P>
|
||||
<P>This pair styles supports the <A HREF = "pair_modify.html">pair_modify</A> shift
|
||||
option for the energy of the Lennard-Jones portion of the pair
|
||||
interaction, but only for sphere-sphere interactions. There is no
|
||||
shifting performed for ellipsoidal interactions due to the anisotropic
|
||||
dependence of the interaction.
|
||||
</P>
|
||||
<P>The <A HREF = "pair_modify.html">pair_modify</A> table option is not relevant
|
||||
for this pair style.
|
||||
</P>
|
||||
<P>This pair style does not support the <A HREF = "pair_modify.html">pair_modify</A>
|
||||
tail option for adding long-range tail corrections to energy and
|
||||
pressure.
|
||||
</P>
|
||||
<P>This pair style does not calculate per-atom energy and stress, as used
|
||||
by the <A HREF = "compute_epair_atom.html">compute epair/atom</A>, <A HREF = "compute_stress_atom.html">compute
|
||||
stress/atom</A>, and <A HREF = "dump.html">dump custom</A>
|
||||
commands.
|
||||
</P>
|
||||
<P>This pair style writes its information to <A HREF = "restart.html">binary restart
|
||||
files</A>, so pair_style and pair_coeff commands do not need
|
||||
to be specified in an input script that reads a restart file.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>Can only be used if LAMMPS was built with the "asphere" package.
|
||||
<P>This style is part of the "asphere" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P>The "shift yes" option in <A HREF = "pair_modify.html">pair_modify</A> only applies
|
||||
to sphere-sphere interactions for this potential; there is no shifting
|
||||
performed for ellipsoidal interactions due to the anisotropic
|
||||
dependence of the interaction. The Gay-Berne potential does not
|
||||
become isotropic as r increases <A HREF = "#Everaers">(Everaers)</A>. The
|
||||
distance-of-closest-approach approximation used by LAMMPS becomes less
|
||||
accurate when high-aspect ratio ellipsoids are used.
|
||||
<P>The Gay-Berne potential does not become isotropic as r increases
|
||||
<A HREF = "#Everaers">(Everaers)</A>. The distance-of-closest-approach
|
||||
approximation used by LAMMPS becomes less accurate when high-aspect
|
||||
ratio ellipsoids are used.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
|
|
@ -79,10 +79,6 @@ cutoff (distance units) :ul
|
|||
The last coefficient is optional. If not specified, the global
|
||||
cutoff specified in the pair_style command is used.
|
||||
|
||||
The epsilon and sigma parameters are mixed for I != J atom pairings
|
||||
the same as Lennard-Jones parameters; see the "pair_modify
|
||||
mix"_pair_modify.html documentation for details.
|
||||
|
||||
The epsilon_i and epsilon_j coefficients are actually defined for atom
|
||||
types, not for pairs of atom types. Thus, in a series of pair_coeff
|
||||
commands, they only need to be specified once for each atom type.
|
||||
|
@ -116,17 +112,49 @@ than the full Gay-Berne formula. Thus you should insure epsilon a,b,c
|
|||
are set to 1.0 for spherical particle types and use epsilon and sigma
|
||||
to specify its interaction with other spherical particles.
|
||||
|
||||
:line
|
||||
|
||||
[Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info]:
|
||||
|
||||
For atom type pairs I,J and I != J, the epsilon and sigma coefficients
|
||||
and cutoff distance for this pair style can be mixed. The default mix
|
||||
value is {geometric}. See the "pair_modify" command for details.
|
||||
|
||||
This pair styles supports the "pair_modify"_pair_modify.html shift
|
||||
option for the energy of the Lennard-Jones portion of the pair
|
||||
interaction, but only for sphere-sphere interactions. There is no
|
||||
shifting performed for ellipsoidal interactions due to the anisotropic
|
||||
dependence of the interaction.
|
||||
|
||||
The "pair_modify"_pair_modify.html table option is not relevant
|
||||
for this pair style.
|
||||
|
||||
This pair style does not support the "pair_modify"_pair_modify.html
|
||||
tail option for adding long-range tail corrections to energy and
|
||||
pressure.
|
||||
|
||||
This pair style does not calculate per-atom energy and stress, as used
|
||||
by the "compute epair/atom"_compute_epair_atom.html, "compute
|
||||
stress/atom"_compute_stress_atom.html, and "dump custom"_dump.html
|
||||
commands.
|
||||
|
||||
This pair style writes its information to "binary restart
|
||||
files"_restart.html, so pair_style and pair_coeff commands do not need
|
||||
to be specified in an input script that reads a restart file.
|
||||
|
||||
:line
|
||||
|
||||
[Restrictions:]
|
||||
|
||||
Can only be used if LAMMPS was built with the "asphere" package.
|
||||
This style is part of the "asphere" package. It is only enabled if
|
||||
LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
The "shift yes" option in "pair_modify"_pair_modify.html only applies
|
||||
to sphere-sphere interactions for this potential; there is no shifting
|
||||
performed for ellipsoidal interactions due to the anisotropic
|
||||
dependence of the interaction. The Gay-Berne potential does not
|
||||
become isotropic as r increases "(Everaers)"_#Everaers. The
|
||||
distance-of-closest-approach approximation used by LAMMPS becomes less
|
||||
accurate when high-aspect ratio ellipsoids are used.
|
||||
The Gay-Berne potential does not become isotropic as r increases
|
||||
"(Everaers)"_#Everaers. The distance-of-closest-approach
|
||||
approximation used by LAMMPS becomes less accurate when high-aspect
|
||||
ratio ellipsoids are used.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
|
|
@ -75,7 +75,7 @@ command.
|
|||
<P><B>Restrictions:</B> none
|
||||
</P>
|
||||
<P>All of these styles are part of the "granular" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_2">Making
|
||||
enabled if LAMMPS was built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
</P>
|
||||
<P>You must use <A HREF = "atom_style.html">atom style</A> <I>granular</I> with these pair
|
||||
|
|
|
@ -67,7 +67,7 @@ See the citation for more discussion of the granular potentials.
|
|||
|
||||
All of these styles are part of the "granular" package. It is only
|
||||
enabled if LAMMPS was built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_2 section for more info.
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
|
||||
You must use "atom style"_atom_style.html {granular} with these pair
|
||||
styles.
|
||||
|
|
|
@ -139,7 +139,7 @@ how to use the TIP4P pair style.
|
|||
types via the <A HREF = "pair_coeff.html">pair_coeff</A> command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
<A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A>
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
</P>
|
||||
<UL><LI>epsilon (energy units)
|
||||
<LI>sigma (distance units)
|
||||
|
@ -163,13 +163,49 @@ can be specified since a Coulombic cutoff cannot be specified for an
|
|||
individual I,J type pair. All type pairs use the same global
|
||||
Coulombic cutoff specified in the pair_style command.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info</B>:
|
||||
</P>
|
||||
<P>For atom type pairs I,J and I != J, the epsilon and sigma coefficients
|
||||
and cutoff distance for all of the lj/cut pair styles can be mixed.
|
||||
The default mix value is <I>geometric</I>. See the "pair_modify" command
|
||||
for details.
|
||||
</P>
|
||||
<P>All of the lj/cut pair styles support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> shift option for the energy of the
|
||||
Lennard-Jones portion of the pair interaction.
|
||||
</P>
|
||||
<P>The <I>lj/cut/coul/long</I> and <I>lj/cut/coul/long/tip4p</I> pair styles
|
||||
support the <A HREF = "pair_modify.html">pair_modify</A> table option since they can
|
||||
tabulate the short-range portion of the long-range Coulombic
|
||||
interaction.
|
||||
</P>
|
||||
<P>All of the lj/cut pair styles support the
|
||||
<A HREF = "pair_modify.html">pair_modify</A> tail option for adding a long-range
|
||||
tail correction to the energy and pressure of the Lennard-Jones
|
||||
portion of the pair interaction.
|
||||
</P>
|
||||
<P>All of the lj/cut pair styles can calculate per-atom energy and
|
||||
stress, as used by the <A HREF = "compute_epair_atom.html">compute epair/atom</A>,
|
||||
<A HREF = "compute_stress_atom.html">compute stress/atom</A>, and <A HREF = "dump.html">dump
|
||||
custom</A> commands.
|
||||
</P>
|
||||
<P>All of the lj/cut pair styles write their information to <A HREF = "restart.html">binary
|
||||
restart files</A>, so pair_style and pair_coeff commands do
|
||||
not need to be specified in an input script that reads a restart file.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
<P><B>Restrictions:</B>
|
||||
</P>
|
||||
<P>The <I>lj/cut/coul/long</I> style is part of the "kspace" package. It is
|
||||
only enabled if LAMMPS was built with that package. The <I>lj/cut/opt</I>
|
||||
style is part of the "opt" package. It is only enabled if LAMMPS was
|
||||
built with that package. See the <A HREF = "Section_start.html#2_3">Making
|
||||
LAMMPS</A> section for more info.
|
||||
<P>The <I>lj/cut/coul/long</I> and <I>lj/cut/coul/long/tip4p</I> styles are part of
|
||||
the "kspace" package. They are only enabled if LAMMPS was built with
|
||||
that package (which it is by default). The <I>lj/cut/opt</I> style is part
|
||||
of the "opt" package. It is only enabled if LAMMPS was built with
|
||||
that package. See the <A HREF = "Section_start.html#2_3">Making LAMMPS</A> section
|
||||
for more info.
|
||||
</P>
|
||||
<P>On some 64-bit machines, compiling with -O3 appears to break the
|
||||
Coulombic tabling option used by the <I>lj/cut/coul/long</I> style. See
|
||||
|
|
|
@ -131,7 +131,7 @@ The following coefficients must be defined for each pair of atoms
|
|||
types via the "pair_coeff"_pair_coeff.html command as in the examples
|
||||
above, or in the data file or restart files read by the
|
||||
"read_data"_read_data.html or "read_restart"_read_restart.html
|
||||
commands:
|
||||
commands, or by mixing as described below:
|
||||
|
||||
epsilon (energy units)
|
||||
sigma (distance units)
|
||||
|
@ -155,13 +155,49 @@ can be specified since a Coulombic cutoff cannot be specified for an
|
|||
individual I,J type pair. All type pairs use the same global
|
||||
Coulombic cutoff specified in the pair_style command.
|
||||
|
||||
:line
|
||||
|
||||
[Mixing, shift, table, tail correction, per-atom energy/stress, and
|
||||
restart info]:
|
||||
|
||||
For atom type pairs I,J and I != J, the epsilon and sigma coefficients
|
||||
and cutoff distance for all of the lj/cut pair styles can be mixed.
|
||||
The default mix value is {geometric}. See the "pair_modify" command
|
||||
for details.
|
||||
|
||||
All of the lj/cut pair styles support the
|
||||
"pair_modify"_pair_modify.html shift option for the energy of the
|
||||
Lennard-Jones portion of the pair interaction.
|
||||
|
||||
The {lj/cut/coul/long} and {lj/cut/coul/long/tip4p} pair styles
|
||||
support the "pair_modify"_pair_modify.html table option since they can
|
||||
tabulate the short-range portion of the long-range Coulombic
|
||||
interaction.
|
||||
|
||||
All of the lj/cut pair styles support the
|
||||
"pair_modify"_pair_modify.html tail option for adding a long-range
|
||||
tail correction to the energy and pressure of the Lennard-Jones
|
||||
portion of the pair interaction.
|
||||
|
||||
All of the lj/cut pair styles can calculate per-atom energy and
|
||||
stress, as used by the "compute epair/atom"_compute_epair_atom.html,
|
||||
"compute stress/atom"_compute_stress_atom.html, and "dump
|
||||
custom"_dump.html commands.
|
||||
|
||||
All of the lj/cut pair styles write their information to "binary
|
||||
restart files"_restart.html, so pair_style and pair_coeff commands do
|
||||
not need to be specified in an input script that reads a restart file.
|
||||
|
||||
:line
|
||||
|
||||
[Restrictions:]
|
||||
|
||||
The {lj/cut/coul/long} style is part of the "kspace" package. It is
|
||||
only enabled if LAMMPS was built with that package. The {lj/cut/opt}
|
||||
style is part of the "opt" package. It is only enabled if LAMMPS was
|
||||
built with that package. See the "Making
|
||||
LAMMPS"_Section_start.html#2_3 section for more info.
|
||||
The {lj/cut/coul/long} and {lj/cut/coul/long/tip4p} styles are part of
|
||||
the "kspace" package. They are only enabled if LAMMPS was built with
|
||||
that package (which it is by default). The {lj/cut/opt} style is part
|
||||
of the "opt" package. It is only enabled if LAMMPS was built with
|
||||
that package. See the "Making LAMMPS"_Section_start.html#2_3 section
|
||||
for more info.
|
||||
|
||||
On some 64-bit machines, compiling with -O3 appears to break the
|
||||
Coulombic tabling option used by the {lj/cut/coul/long} style. See
|
||||
|
|
|
@ -19,8 +19,8 @@
|
|||
|
||||
<LI>keyword = <I>shift</I> or <I>mix</I> or <I>table</I> or <I>tabinner</I> or <I>tail</I>
|
||||
|
||||
<PRE> <I>shift</I> value = <I>yes</I> or <I>no</I>
|
||||
<I>mix</I> value = <I>geometric</I> or <I>arithmetic</I> or <I>sixthpower</I>
|
||||
<PRE> <I>mix</I> value = <I>geometric</I> or <I>arithmetic</I> or <I>sixthpower</I>
|
||||
<I>shift</I> value = <I>yes</I> or <I>no</I>
|
||||
<I>table</I> value = N
|
||||
2^N = # of values in table
|
||||
<I>tabinner</I> value = cutoff
|
||||
|
@ -40,51 +40,56 @@ pair_modify table 12
|
|||
<P>Modify the parameters of the currently defined pair style. Not all
|
||||
parameters are relevant to all pair styles.
|
||||
</P>
|
||||
<P>The <I>shift</I> keyword determines whether the Lennard-Jones potential is
|
||||
shifted at its cutoff to 0.0. If so, this adds an energy term to each
|
||||
pairwise interaction which will be printed in the thermodynamic
|
||||
output, but does not affect atom dynamics (forces). Pair styles that
|
||||
are already 0.0 at their cutoff such as <I>lj/charmm/coul/charmm</I> are
|
||||
not affected by this setting.
|
||||
<P>The <I>mix</I> keyword affects pair coefficients for interactions between
|
||||
atoms of type I and J, when I != J and the coefficients are not
|
||||
explicity set in the input script. Note that coefficients for I = J
|
||||
must be set explicitly, either in the input script via the
|
||||
"pair_coeff" command or in the "Pair Coeffs" section of the <A HREF = "read_data.html">data
|
||||
file</A>. For some pair styles is is not necessary to
|
||||
specify coefficients when I != J, since a "mixing" rule will create
|
||||
them from the I,I and J,J settings. The pair_modify <I>mix</I> value
|
||||
determines what formulas are used to compute the mixed coefficients.
|
||||
In each case, the cutoff distance is mixed the same way as sigma.
|
||||
</P>
|
||||
<P>The <I>mix</I> keyword affects how Lennard-Jones coefficients for epsilon,
|
||||
sigma, and the cutoff are generated for interactions between atoms of
|
||||
type I and J, when I != J. Coefficients for I = J are set explicitly
|
||||
in the data file or input script. The <A HREF = "pair_coeff.html">pair_coeff</A>
|
||||
command can be used in the input script to specify epilon/sigma for a
|
||||
specific I != J pairing, which overrides the setting of the <I>mix</I>
|
||||
keyword.
|
||||
<P>Note that not all pair styles support mixing. Also, some mix options
|
||||
are not available for certain pair styles. See the doc page for
|
||||
individual pair styles for those restrictions. Note also that the
|
||||
<A HREF = "pair_coeff.html">pair_coeff</A> command also can be to directly set
|
||||
coefficients for a specific I != J pairing, in which case no mixing is
|
||||
performed.
|
||||
</P>
|
||||
<P>These are the formulas used by the 3 <I>mix</I> options. In each case, the
|
||||
LJ cutoff is mixed the same way as sigma. Note that some of these
|
||||
options are not available for certain pair styles. See the doc page
|
||||
for individual pair styles for those restrictions.
|
||||
</P>
|
||||
<P><I>geometric</I>
|
||||
<P>mix <I>geometric</I>
|
||||
</P>
|
||||
<PRE>epsilon_ij = sqrt(epsilon_i * epsilon_j)
|
||||
sigma_ij = sqrt(sigma_i * sigma_j)
|
||||
</PRE>
|
||||
<P><I>arithmetic</I>
|
||||
<P>mix <I>arithmetic</I>
|
||||
</P>
|
||||
<PRE>epsilon_ij = sqrt(epsilon_i * epsilon_j)
|
||||
sigma_ij = (sigma_i + sigma_j) / 2
|
||||
</PRE>
|
||||
<P><I>sixthpower</I>
|
||||
<P>mix <I>sixthpower</I>
|
||||
</P>
|
||||
<PRE>epsilon_ij = (2 * sqrt(epsilon_i*epsilon_j) * sigma_i^3 * sigma_j^3) /
|
||||
(sigma_i^6 + sigma_j^6)
|
||||
sigma_ij = ((sigma_i**6 + sigma_j**6) / 2) ^ (1/6)
|
||||
</PRE>
|
||||
<P>The <I>shift</I> keyword determines whether a Lennard-Jones potential is
|
||||
shifted at its cutoff to 0.0. If so, this adds an energy term to each
|
||||
pairwise interaction which will be included in the thermodynamic
|
||||
output, but does not affect pair forces or atom trajectories. See the
|
||||
doc page for individual pair styles to see which ones support this
|
||||
option.
|
||||
</P>
|
||||
<P>The <I>table</I> keyword applies to pair styles with a long-range Coulombic
|
||||
term (lj/cut/coul/long and lj/charmm/coul/long). If N is non-zero, a
|
||||
table of length 2^N is pre-computed for forces and energies, which can
|
||||
shrink their computational cost by up to a factor of 2. The table is
|
||||
indexed via a bit-mapping technique <A HREF = "#Wolff">(Wolff)</A> and a linear
|
||||
interpolation is performed between adjacent table values. In our
|
||||
experiments with different table styles (lookup, linear, spline), this
|
||||
method typically gave the best performance in terms of speed and
|
||||
accuracy.
|
||||
term; see the doc page for individual styles to see which potentials
|
||||
support this option. If N is non-zero, a table of length 2^N is
|
||||
pre-computed for forces and energies, which can shrink their
|
||||
computational cost by up to a factor of 2. The table is indexed via a
|
||||
bit-mapping technique <A HREF = "#Wolff">(Wolff)</A> and a linear interpolation is
|
||||
performed between adjacent table values. In our experiments with
|
||||
different table styles (lookup, linear, spline), this method typically
|
||||
gave the best performance in terms of speed and accuracy.
|
||||
</P>
|
||||
<P>The choice of table length is a tradeoff in accuracy versus speed. A
|
||||
larger N yields more accurate force computations, but requires more
|
||||
|
@ -106,19 +111,16 @@ nearly all pairwise interactions are computed via table lookup for
|
|||
simulations with "real" units, but some close pairs may be computed
|
||||
directly (non-table) for simulations with "lj" units.
|
||||
</P>
|
||||
<P>When the <I>tail</I> keyword is set to <I>yes</I>, long-range VanderWaals tail
|
||||
"corrections" are added to the energy and pressure. These are
|
||||
included in the calculation and printing of thermodynamic quantities
|
||||
(see the <A HREF = "thermo_style.html">thermo_style</A> command). Their effect will
|
||||
also be included in constant NPT or NPH simulations where the pressure
|
||||
influences the simulation box dimensions (see the <A HREF = "fix_npt.html">fix
|
||||
npt</A> and <A HREF = "fix_nph.html">fix nph</A> commands).
|
||||
</P>
|
||||
<P>The <I>tail</I> keyword is only supported by <A HREF = "pair_style.html">pair_style</A>
|
||||
pairwise potentials which include Lennard-Jones interactions which are
|
||||
cutoff at a non-zero energy. This does not include the LJ CHARMM
|
||||
potentials or <I>lj/smooth</I> since they go to zero at the cutoff. The
|
||||
formulas used for the long-range corrections come from equation 5 of
|
||||
<P>When the <I>tail</I> keyword is set to <I>yes</I>, certain pair styles will add
|
||||
a long-range VanderWaals tail "correction" to the energy and pressure.
|
||||
See the doc page for individual styles to see which support this
|
||||
option. These corrections are included in the calculation and
|
||||
printing of thermodynamic quantities (see the
|
||||
<A HREF = "thermo_style.html">thermo_style</A> command). Their effect will also be
|
||||
included in constant NPT or NPH simulations where the pressure
|
||||
influences the simulation box dimensions (e.g. the <A HREF = "fix_npt.html">fix
|
||||
npt</A> and <A HREF = "fix_nph.html">fix nph</A> commands). The formulas
|
||||
used for the long-range corrections come from equation 5 of
|
||||
<A HREF = "#Sun">(Sun)</A>.
|
||||
</P>
|
||||
<P>Several assumptions are inherent in using tail corrections, including
|
||||
|
@ -144,13 +146,8 @@ those interactions.
|
|||
</UL>
|
||||
<P><B>Restrictions:</B> none
|
||||
</P>
|
||||
<P>Not all pair styles support mixing. See the doc page for individual
|
||||
pair styles for details.
|
||||
</P>
|
||||
<P>You cannot use <I>shift</I> yes with <I>tail</I> yes, since those are
|
||||
conflicting options.
|
||||
</P>
|
||||
<P>You cannot use <I>tail</I> yes with 2d simulations.
|
||||
conflicting options. You cannot use <I>tail</I> yes with 2d simulations.
|
||||
</P>
|
||||
<P><B>Related commands:</B>
|
||||
</P>
|
||||
|
@ -159,9 +156,11 @@ conflicting options.
|
|||
</P>
|
||||
<P><B>Default:</B>
|
||||
</P>
|
||||
<P>The option defaults are shift = no, mix = arithmetic (for lj/charmm
|
||||
pair styles), mix = geometric (for other pair styles), table = 12,
|
||||
and tabinner = sqrt(2.0), tail = no.
|
||||
<P>The option defaults are mix = geometric, shift = no, table = 12,
|
||||
tabinner = sqrt(2.0), tail = no.
|
||||
</P>
|
||||
<P>Note that some pair styles perform mixing, but only a certain style of
|
||||
mixing. See the doc pages for individual pair styles for details.
|
||||
</P>
|
||||
<HR>
|
||||
|
||||
|
|
|
@ -14,8 +14,8 @@ pair_modify keyword value ... :pre
|
|||
|
||||
one or more keyword/value pairs may be listed :ulb,l
|
||||
keyword = {shift} or {mix} or {table} or {tabinner} or {tail} :l
|
||||
{shift} value = {yes} or {no}
|
||||
{mix} value = {geometric} or {arithmetic} or {sixthpower}
|
||||
{shift} value = {yes} or {no}
|
||||
{table} value = N
|
||||
2^N = # of values in table
|
||||
{tabinner} value = cutoff
|
||||
|
@ -34,51 +34,56 @@ pair_modify table 12 :pre
|
|||
Modify the parameters of the currently defined pair style. Not all
|
||||
parameters are relevant to all pair styles.
|
||||
|
||||
The {shift} keyword determines whether the Lennard-Jones potential is
|
||||
shifted at its cutoff to 0.0. If so, this adds an energy term to each
|
||||
pairwise interaction which will be printed in the thermodynamic
|
||||
output, but does not affect atom dynamics (forces). Pair styles that
|
||||
are already 0.0 at their cutoff such as {lj/charmm/coul/charmm} are
|
||||
not affected by this setting.
|
||||
The {mix} keyword affects pair coefficients for interactions between
|
||||
atoms of type I and J, when I != J and the coefficients are not
|
||||
explicity set in the input script. Note that coefficients for I = J
|
||||
must be set explicitly, either in the input script via the
|
||||
"pair_coeff" command or in the "Pair Coeffs" section of the "data
|
||||
file"_read_data.html. For some pair styles is is not necessary to
|
||||
specify coefficients when I != J, since a "mixing" rule will create
|
||||
them from the I,I and J,J settings. The pair_modify {mix} value
|
||||
determines what formulas are used to compute the mixed coefficients.
|
||||
In each case, the cutoff distance is mixed the same way as sigma.
|
||||
|
||||
The {mix} keyword affects how Lennard-Jones coefficients for epsilon,
|
||||
sigma, and the cutoff are generated for interactions between atoms of
|
||||
type I and J, when I != J. Coefficients for I = J are set explicitly
|
||||
in the data file or input script. The "pair_coeff"_pair_coeff.html
|
||||
command can be used in the input script to specify epilon/sigma for a
|
||||
specific I != J pairing, which overrides the setting of the {mix}
|
||||
keyword.
|
||||
Note that not all pair styles support mixing. Also, some mix options
|
||||
are not available for certain pair styles. See the doc page for
|
||||
individual pair styles for those restrictions. Note also that the
|
||||
"pair_coeff"_pair_coeff.html command also can be to directly set
|
||||
coefficients for a specific I != J pairing, in which case no mixing is
|
||||
performed.
|
||||
|
||||
These are the formulas used by the 3 {mix} options. In each case, the
|
||||
LJ cutoff is mixed the same way as sigma. Note that some of these
|
||||
options are not available for certain pair styles. See the doc page
|
||||
for individual pair styles for those restrictions.
|
||||
|
||||
{geometric}
|
||||
mix {geometric}
|
||||
|
||||
epsilon_ij = sqrt(epsilon_i * epsilon_j)
|
||||
sigma_ij = sqrt(sigma_i * sigma_j) :pre
|
||||
|
||||
{arithmetic}
|
||||
mix {arithmetic}
|
||||
|
||||
epsilon_ij = sqrt(epsilon_i * epsilon_j)
|
||||
sigma_ij = (sigma_i + sigma_j) / 2 :pre
|
||||
|
||||
{sixthpower}
|
||||
mix {sixthpower}
|
||||
|
||||
epsilon_ij = (2 * sqrt(epsilon_i*epsilon_j) * sigma_i^3 * sigma_j^3) /
|
||||
(sigma_i^6 + sigma_j^6)
|
||||
sigma_ij = ((sigma_i**6 + sigma_j**6) / 2) ^ (1/6) :pre
|
||||
|
||||
The {shift} keyword determines whether a Lennard-Jones potential is
|
||||
shifted at its cutoff to 0.0. If so, this adds an energy term to each
|
||||
pairwise interaction which will be included in the thermodynamic
|
||||
output, but does not affect pair forces or atom trajectories. See the
|
||||
doc page for individual pair styles to see which ones support this
|
||||
option.
|
||||
|
||||
The {table} keyword applies to pair styles with a long-range Coulombic
|
||||
term (lj/cut/coul/long and lj/charmm/coul/long). If N is non-zero, a
|
||||
table of length 2^N is pre-computed for forces and energies, which can
|
||||
shrink their computational cost by up to a factor of 2. The table is
|
||||
indexed via a bit-mapping technique "(Wolff)"_#Wolff and a linear
|
||||
interpolation is performed between adjacent table values. In our
|
||||
experiments with different table styles (lookup, linear, spline), this
|
||||
method typically gave the best performance in terms of speed and
|
||||
accuracy.
|
||||
term; see the doc page for individual styles to see which potentials
|
||||
support this option. If N is non-zero, a table of length 2^N is
|
||||
pre-computed for forces and energies, which can shrink their
|
||||
computational cost by up to a factor of 2. The table is indexed via a
|
||||
bit-mapping technique "(Wolff)"_#Wolff and a linear interpolation is
|
||||
performed between adjacent table values. In our experiments with
|
||||
different table styles (lookup, linear, spline), this method typically
|
||||
gave the best performance in terms of speed and accuracy.
|
||||
|
||||
The choice of table length is a tradeoff in accuracy versus speed. A
|
||||
larger N yields more accurate force computations, but requires more
|
||||
|
@ -100,19 +105,16 @@ nearly all pairwise interactions are computed via table lookup for
|
|||
simulations with "real" units, but some close pairs may be computed
|
||||
directly (non-table) for simulations with "lj" units.
|
||||
|
||||
When the {tail} keyword is set to {yes}, long-range VanderWaals tail
|
||||
"corrections" are added to the energy and pressure. These are
|
||||
included in the calculation and printing of thermodynamic quantities
|
||||
(see the "thermo_style"_thermo_style.html command). Their effect will
|
||||
also be included in constant NPT or NPH simulations where the pressure
|
||||
influences the simulation box dimensions (see the "fix
|
||||
npt"_fix_npt.html and "fix nph"_fix_nph.html commands).
|
||||
|
||||
The {tail} keyword is only supported by "pair_style"_pair_style.html
|
||||
pairwise potentials which include Lennard-Jones interactions which are
|
||||
cutoff at a non-zero energy. This does not include the LJ CHARMM
|
||||
potentials or {lj/smooth} since they go to zero at the cutoff. The
|
||||
formulas used for the long-range corrections come from equation 5 of
|
||||
When the {tail} keyword is set to {yes}, certain pair styles will add
|
||||
a long-range VanderWaals tail "correction" to the energy and pressure.
|
||||
See the doc page for individual styles to see which support this
|
||||
option. These corrections are included in the calculation and
|
||||
printing of thermodynamic quantities (see the
|
||||
"thermo_style"_thermo_style.html command). Their effect will also be
|
||||
included in constant NPT or NPH simulations where the pressure
|
||||
influences the simulation box dimensions (e.g. the "fix
|
||||
npt"_fix_npt.html and "fix nph"_fix_nph.html commands). The formulas
|
||||
used for the long-range corrections come from equation 5 of
|
||||
"(Sun)"_#Sun.
|
||||
|
||||
Several assumptions are inherent in using tail corrections, including
|
||||
|
@ -138,13 +140,8 @@ those interactions. :l,ule
|
|||
|
||||
[Restrictions:] none
|
||||
|
||||
Not all pair styles support mixing. See the doc page for individual
|
||||
pair styles for details.
|
||||
|
||||
You cannot use {shift} yes with {tail} yes, since those are
|
||||
conflicting options.
|
||||
|
||||
You cannot use {tail} yes with 2d simulations.
|
||||
conflicting options. You cannot use {tail} yes with 2d simulations.
|
||||
|
||||
[Related commands:]
|
||||
|
||||
|
@ -153,9 +150,11 @@ You cannot use {tail} yes with 2d simulations.
|
|||
|
||||
[Default:]
|
||||
|
||||
The option defaults are shift = no, mix = arithmetic (for lj/charmm
|
||||
pair styles), mix = geometric (for other pair styles), table = 12,
|
||||
and tabinner = sqrt(2.0), tail = no.
|
||||
The option defaults are mix = geometric, shift = no, table = 12,
|
||||
tabinner = sqrt(2.0), tail = no.
|
||||
|
||||
Note that some pair styles perform mixing, but only a certain style of
|
||||
mixing. See the doc pages for individual pair styles for details.
|
||||
|
||||
:line
|
||||
|
||||
|
|
Some files were not shown because too many files have changed in this diff Show More
Loading…
Reference in New Issue