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