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sjplimp 2006-11-11 00:08:49 +00:00
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commit ebcbf94231
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3
doc/fix.html
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@ -98,7 +98,8 @@ integrators would be in place!
<LI><A HREF = "fix_viscous.html">fix viscous</A> - viscous damping for granular simulations
<LI><A HREF = "fix_volume_rescale.html">fix volume/rescale</A> - density control by volume rescaling
<LI><A HREF = "fix_wall_gran.html">fix wall/gran</A> - frictional wall(s) for granular simulations
<LI><A HREF = "fix_wall_lj93.html">fix wall/lj93</A> - Lennard-Jones 9/3 wall
<LI><A HREF = "fix_wall_lj93.html">fix wall/lj93</A> - Lennard-Jones 9-3 wall
<LI><A HREF = "fix_wall_lj126.html">fix wall/lj126</A> - Lennard-Jones 12-6 wall
<LI><A HREF = "fix_wall_reflect.html">fix wall/reflect</A> - reflecting wall(s)
<LI><A HREF = "fix_wiggle.html">fix wiggle</A> - oscillate walls and frozen atoms
</UL>

3
doc/fix.txt
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@ -106,7 +106,8 @@ Here is an alphabetic list of fix styles defined in LAMMPS:
volume rescaling
"fix wall/gran"_fix_wall_gran.html - frictional wall(s) for \
granular simulations
"fix wall/lj93"_fix_wall_lj93.html - Lennard-Jones 9/3 wall
"fix wall/lj93"_fix_wall_lj93.html - Lennard-Jones 9-3 wall
"fix wall/lj126"_fix_wall_lj126.html - Lennard-Jones 12-6 wall
"fix wall/reflect"_fix_wall_reflect.html - reflecting wall(s)
"fix wiggle"_fix_wiggle.html - oscillate walls and frozen atoms :ul

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doc/fix_wall_lj126.html Normal file
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@ -0,0 +1,69 @@
<HTML>
<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A>
</CENTER>
<HR>
<H3>fix wall/lj126 command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>fix ID group-ID wall/lj126 style coord epsilon sigma cutoff
</PRE>
<UL><LI>ID, group-ID are documented in <A HREF = "fix.html">fix</A> command
<LI>wall/lj126 = style name of this fix command
<LI>style = <I>xlo</I> or <I>xhi</I> or <I>ylo</I> or <I>yhi</I> or <I>zlo</I> or <I>zhi</I>
<LI>coord = position of wall
<LI>epsilon = Lennard-Jones epsilon for wall-particle interaction
<LI>sigma = Lennard-Jones sigma for wall-particle interaction
<LI>cutoff = distance from wall at which wall-particle interaction is cut off
</UL>
<P><B>Examples:</B>
</P>
<PRE>fix wallhi all wall/lj126 xhi 10.0 1.0 1.0 1.12
</PRE>
<P><B>Description:</B>
</P>
<P>Bound the simulation domain with a Lennard-Jones wall that encloses
the atoms. The energy E of a wall-particle interactions is given by
the 12-6 potential
</P>
<CENTER><IMG SRC = "Eqs/pair_lj.jpg">
</CENTER>
<P>where <I>r</I> is the distance from the particle to the wall <I>coord</I>, and
epsilon and sigma are the usual LJ parameters. Rc is the cutoff value
specified in the command. This interaction provides a harder, more
repulsive interaction with the wall than the softer 9-3 potential
provided by the <A HREF = "fix_wall_lj93.html">fix wall/lj93</A> command.
</P>
<P>The wall potential is shifted so that the energy of a wall-particle
interaction is 0.0 at the cutoff distance.
</P>
<P>This fix supports the <A HREF = "fix_modify.html">fix_modify</A> options for
<I>thermo</I> and <I>energy</I>. The former will print the contribution the fix
makes to the energy of the system when thermodynamics is printed,
where the energy of each particle comes from the integrated form of
the equation above. The latter will add this contribution to the
total potential energy (PotEng).
</P>
<P>The forces due to this fix are also imposed during an energy
minimization, invoked by the <A HREF = "minimize.html">minimize</A> command. If you
want that energy to be included in the total potential energy of the
system (the quantity being minimized), you must enable the
<A HREF = "fix_modify.html">fix_modify</A> <I>energy</I> option for this fix.
</P>
<P><B>Restrictions:</B> none
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "fix_wall_reflect.html">fix wall/reflect</A>, <A HREF = "fix_wall_lj93.html">fix
wall/lj93</A>
</P>
<P><B>Default:</B> none
</P>
</HTML>

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doc/fix_wall_lj126.txt Normal file
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@ -0,0 +1,64 @@
"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)
:line
fix wall/lj126 command :h3
[Syntax:]
fix ID group-ID wall/lj126 style coord epsilon sigma cutoff :pre
ID, group-ID are documented in "fix"_fix.html command
wall/lj126 = style name of this fix command
style = {xlo} or {xhi} or {ylo} or {yhi} or {zlo} or {zhi}
coord = position of wall
epsilon = Lennard-Jones epsilon for wall-particle interaction
sigma = Lennard-Jones sigma for wall-particle interaction
cutoff = distance from wall at which wall-particle interaction is cut off :ul
[Examples:]
fix wallhi all wall/lj126 xhi 10.0 1.0 1.0 1.12 :pre
[Description:]
Bound the simulation domain with a Lennard-Jones wall that encloses
the atoms. The energy E of a wall-particle interactions is given by
the 12-6 potential
:c,image(Eqs/pair_lj.jpg)
where {r} is the distance from the particle to the wall {coord}, and
epsilon and sigma are the usual LJ parameters. Rc is the cutoff value
specified in the command. This interaction provides a harder, more
repulsive interaction with the wall than the softer 9-3 potential
provided by the "fix wall/lj93"_fix_wall_lj93.html command.
The wall potential is shifted so that the energy of a wall-particle
interaction is 0.0 at the cutoff distance.
This fix supports the "fix_modify"_fix_modify.html options for
{thermo} and {energy}. The former will print the contribution the fix
makes to the energy of the system when thermodynamics is printed,
where the energy of each particle comes from the integrated form of
the equation above. The latter will add this contribution to the
total potential energy (PotEng).
The forces due to this fix are also imposed during an energy
minimization, invoked by the "minimize"_minimize.html command. If you
want that energy to be included in the total potential energy of the
system (the quantity being minimized), you must enable the
"fix_modify"_fix_modify.html {energy} option for this fix.
[Restrictions:] none
[Related commands:]
"fix wall/reflect"_fix_wall_reflect.html, "fix
wall/lj93"_fix_wall_lj93.html
[Default:] none

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doc/fix_wall_lj93.html
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@ -25,7 +25,7 @@
</UL>
<P><B>Examples:</B>
</P>
<PRE>fix wallhi all wall/lj93 xhi 10.0 1.0 1.0 1.12
<PRE>fix wallhi all wall/lj93 xhi 10.0 1.0 1.0 2.5
</PRE>
<P><B>Description:</B>
</P>
@ -38,7 +38,12 @@ the 9-3 potential
<P>where <I>r</I> is the distance from the particle to the wall <I>coord</I>, and
epsilon and sigma are the usual LJ parameters. Rc is the cutoff value
specified in the command. This interaction is derived by integrating
over a 3d half-lattice of Lennard-Jones 12-6 particles.
over a 3d half-lattice of Lennard-Jones 12-6 particles. A harder,
more repulsive wall interaction can be computed by using the <A HREF = "fix_wall_lj126.html">fix
wall/lj126</A> command.
</P>
<P>The wall potential is shifted so that the energy of a wall-particle
interaction is 0.0 at the cutoff distance.
</P>
<P>This fix supports the <A HREF = "fix_modify.html">fix_modify</A> options for
<I>thermo</I> and <I>energy</I>. The former will print the contribution the fix
@ -57,7 +62,8 @@ system (the quantity being minimized), you must enable the
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "fix_wall_reflect.html">fix wall/reflect</A> command
<P><A HREF = "fix_wall_reflect.html">fix wall/reflect</A>, <A HREF = "fix_wall_lj126.html">fix
wall/lj126</A>
</P>
<P><B>Default:</B> none
</P>

12
doc/fix_wall_lj93.txt
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@ -22,7 +22,7 @@ cutoff = distance from wall at which wall-particle interaction is cut off :ul
[Examples:]
fix wallhi all wall/lj93 xhi 10.0 1.0 1.0 1.12 :pre
fix wallhi all wall/lj93 xhi 10.0 1.0 1.0 2.5 :pre
[Description:]
@ -35,7 +35,12 @@ the 9-3 potential
where {r} is the distance from the particle to the wall {coord}, and
epsilon and sigma are the usual LJ parameters. Rc is the cutoff value
specified in the command. This interaction is derived by integrating
over a 3d half-lattice of Lennard-Jones 12-6 particles.
over a 3d half-lattice of Lennard-Jones 12-6 particles. A harder,
more repulsive wall interaction can be computed by using the "fix
wall/lj126"_fix_wall_lj126.html command.
The wall potential is shifted so that the energy of a wall-particle
interaction is 0.0 at the cutoff distance.
This fix supports the "fix_modify"_fix_modify.html options for
{thermo} and {energy}. The former will print the contribution the fix
@ -54,6 +59,7 @@ system (the quantity being minimized), you must enable the
[Related commands:]
"fix wall/reflect"_fix_wall_reflect.html command
"fix wall/reflect"_fix_wall_reflect.html, "fix
wall/lj126"_fix_wall_lj126.html
[Default:] none