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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>
</CENTER>
<HR>
<H3>comm_style command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>comm_style style
</PRE>
<UL><LI>style = <I>brick</I> or <I>tiled</I>
</UL>
<P><B>Examples:</B>
</P>
<PRE>comm_style brick
comm_style tiled
</PRE>
<P><B>Description:</B>
</P>
<P>This command sets the style of inter-processor communication of atom
information that occurs each timestep as coordinates and other
properties are exchanged between neighboring processors and stored as
properties of ghost atoms.
</P>
<P>For the default <I>brick</I> style, the domain decomposition used by LAMMPS
to partition the simulation box must be a regular 3d grid of bricks,
one per processor. Each processor communicates with its 6 Cartesian
neighbors in the grid to acquire information for nearby atoms.
</P>
<P>For the <I>tiled</I> style, a more general domain decomposition can be
used, as triggered by the <A HREF = "balance.html">balance</A> or <A HREF = "fix_balance.html">fix
balance</A> commands. The simulation box can be
partitioned into non-overlapping rectangular-shaped "tiles" or varying
sizes and shapes. Again there is one tile per processor. To acquire
information for nearby atoms, communication must now be done with a
more complex pattern of neighboring processors.
</P>
<P>Note that this command does not actually define a partitoining of the
simulation box (a domain decomposition), rather it determines what
kinds of decompositions are allowed and the pattern of communication
used to enable the decomposition. A decomposition is created when the
simulation box is first created, via the <A HREF = "create_box.html">create_box</A>
or <A HREF = "read_data.html">read_data</A> or <A HREF = "read_restart.html">read_restart</A>
commands. For both the <I>brick</I> and <I>tiled</I> styles, the initial
decomposition will be the same, as described by
<A HREF = "create_box.html">create_box</A> and <A HREF = "processors.html">processors</A>
commands. The decomposition can be changed via the
<A HREF = "balance.html">balance</A> or <A HREF = "fix_balance.html">fix_balance</A> commands.
</P>
<P><B>Restrictions:</B> none
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "comm_modify.html">comm_modify</A>, <A HREF = "processors.html">processors</A>,
<A HREF = "balance.html">balance</A>, <A HREF = "fix_balance.html">fix balance</A>
</P>
<P><B>Default:</B>
</P>
<P>The default style is brick.
</P>
</HTML>
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