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<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>pair_style lj96/cut command
</H3>
<H3>pair_style lj96/cut/gpu command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>pair_style style cutoff
</PRE>
<UL><LI>style = <I>lj96/cut</I> or <I>lj96/cut/gpu</I>
<LI>cutoff = global cutoff for lj96/cut interactions (distance units)
</UL>
<P><B>Examples:</B>
</P>
<PRE>pair_style lj96/cut 2.5
pair_style lj96/cut/gpu 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>Style <I>lj96/cut/gpu</I> is a GPU-enabled version of style <I>lj96/cut</I>.
See more details below.
</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>The <I>lj96/cut/gpu</I> style is identical to the <I>lj96/cut</I> style, except
that each processor off-loads its pairwise calculations to a GPU.
Depending on the hardware available on your system this can provide a
speed-up. See <A HREF = "doc/Section_accerate.html">this section</A> of the manual
for more details.
</P>
<P>Additional requirements in your input script to run with the
<I>lj96/cut/gpu</I> style are as follows:
</P>
<P>The <A HREF = "newton.html">newton pair</A> setting must be <I>off</I> and the <A HREF = "fix_gpu.html">fix
gpu</A> command must be used. The fix controls the GPU
selection and initialization steps
</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>
</P>
<P>The <I>lj96/cut/gpu</I> style is part of the "gpu" package. It
is only enabled if LAMMPS is built with this packages. See the
<A HREF = "Section_start.html#2_3">Making LAMMPS</A> section for more info.
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "pair_coeff.html">pair_coeff</A>
</P>
<P><B>Default:</B> none
</P>
</HTML>
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