lammps/doc/pair_lj96.html

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<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>
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<H3>pair_style lj96/cut command
</H3>
<H3>pair_style lj96/cut/cuda command
</H3>
<H3>pair_style lj96/cut/gpu command
</H3>
<H3>pair_style lj96/cut/omp command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>pair_style lj96/cut cutoff
</PRE>
<UL><LI>cutoff = global cutoff for lj96/cut interactions (distance units)
</UL>
<P><B>Examples:</B>
</P>
<PRE>pair_style lj96/cut 2.5
pair_coeff * * 1.0 1.0 4.0
pair_coeff 1 1 1.0 1.0
</PRE>
<P><B>Description:</B>
</P>
<P>The <I>lj96/cut</I> style compute a 9/6 Lennard-Jones potential, instead
of the standard 12/6 potential, given by
</P>
<CENTER><IMG SRC = "Eqs/pair_lj96.jpg">
</CENTER>
<P>Rc is the cutoff.
</P>
<P>The following coefficients must be defined for each pair of atoms
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, or by mixing as described below:
</P>
<UL><LI>epsilon (energy units)
<LI>sigma (distance units)
<LI>cutoff (distance units)
</UL>
<P>The last coefficient is optional. If not specified, the global LJ
cutoff specified in the pair_style command is used.
</P>
<HR>
<P>Styles with a <I>cuda</I>, <I>gpu</I>, <I>omp</I>, or <I>opt</I> suffix are functionally
the same as the corresponding style without the suffix. They have
been optimized to run faster, depending on your available hardware, as
discussed in <A HREF = "Section_accelerate.html">Section_accelerate</A> of the
manual. The accelerated styles take the same arguments and should
produce the same results, except for round-off and precision issues.
</P>
<P>These accelerated styles are part of the USER-CUDA, GPU, USER-OMP and OPT
packages, respectively. They are only enabled if LAMMPS was built with
those packages. See the <A HREF = "Section_start.html#start_3">Making LAMMPS</A>
section for more info.
</P>
<P>You can specify the accelerated styles explicitly in your input script
by including their suffix, or you can use the <A HREF = "Section_start.html#start_7">-suffix command-line
switch</A> when you invoke LAMMPS, or you can
use the <A HREF = "suffix.html">suffix</A> command in your input script.
</P>
<P>See <A HREF = "Section_accelerate.html">Section_accelerate</A> of the manual for
more instructions on how to use the accelerated styles effectively.
</P>
<HR>
<P><B>Mixing, shift, table, tail correction, restart, rRESPA 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>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 supports 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 pair interaction.
</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>This pair style supports the use of the <I>inner</I>, <I>middle</I>, and <I>outer</I>
keywords of the <A HREF = "run_style.html">run_style respa</A> command, meaning the
pairwise forces can be partitioned by distance at different levels of
the rRESPA hierarchy. See the <A HREF = "run_style.html">run_style</A> command for
details.
</P>
<HR>
<P><B>Restrictions:</B> none
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "pair_coeff.html">pair_coeff</A>
</P>
<P><B>Default:</B> none
</P>
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