forked from lijiext/lammps
72 lines
2.6 KiB
HTML
72 lines
2.6 KiB
HTML
<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>replicate command
|
|
</H3>
|
|
<P><B>Syntax:</B>
|
|
</P>
|
|
<PRE>replicate nx ny nz
|
|
</PRE>
|
|
<UL><LI>nx,ny,nz = replication factors in each dimension
|
|
</UL>
|
|
<P><B>Examples:</B>
|
|
</P>
|
|
<PRE>replicate 2 3 2
|
|
</PRE>
|
|
<P><B>Description:</B>
|
|
</P>
|
|
<P>Replicate the current simulation one or more times in each dimension.
|
|
For example, replication factors of 2,2,2 will create a simulation
|
|
with 8x as many atoms by doubling the simulation domain in each
|
|
dimension. A replication factor of 1 in a dimension leaves the
|
|
simulation domain unchanged.
|
|
</P>
|
|
<P>All properties of the atoms are replicated, including their
|
|
velocities, which may or may not be desirable. New atom IDs are
|
|
assigned to new atoms, as are molecule IDs. Bonds and other topology
|
|
interactions are created between pairs of new atoms as well as between
|
|
old and new atoms. This is done by using the image flag for each atom
|
|
to "unwrap" it out of the periodic box before replicating it. This
|
|
means that molecular bonds you specify in the original data file that
|
|
span the periodic box should be between two atoms with image flags
|
|
that differ by 1. This will allow them to be unwrapped appropriately.
|
|
</P>
|
|
<P><B>Restrictions:</B>
|
|
</P>
|
|
<P>A 2d simulation cannot be replicated in the z dimension.
|
|
</P>
|
|
<P>If a simulation is non-periodic in a dimension, care should be used
|
|
when replicating it in that dimension, as it may put atoms nearly on
|
|
top of each other.
|
|
</P>
|
|
<P>If the current simulation was read in from a restart file (before a
|
|
run is performed), there can have been no fix information stored in
|
|
the file for individual atoms. Similarly, no fixes can be defined at
|
|
the time the replicate command is used that require vectors of atom
|
|
information to be stored. This is because the replicate command does
|
|
not know how to replicate that information for new atoms it creates.
|
|
</P>
|
|
<P>Replicating a system that has rigid bodies (defined via the <A HREF = "fix_rigid.html">fix
|
|
rigid</A> command), either currently defined or that
|
|
created the restart file which was read in before replicating, can
|
|
cause problems if there is a bond between a pair of rigid bodies that
|
|
straddle a periodic boundary. This is because the periodic image
|
|
information for particles in the rigid bodies are set differently than
|
|
for a non-rigid system and can result in a new bond being created that
|
|
spans the periodic box. Thus you cannot use the replicate command in
|
|
this scenario.
|
|
</P>
|
|
<P><B>Related commands:</B> none
|
|
</P>
|
|
<P><B>Default:</B> none
|
|
</P>
|
|
</HTML>
|