2006-09-22 00:22:34 +08:00
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"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
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:link(lws,http://lammps.sandia.gov)
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:link(ld,Manual.html)
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:link(lc,Section_commands.html#comm)
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:line
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processors command :h3
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[Syntax:]
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processors Px Py Pz :pre
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Px,Py,Pz = # of processors in each dimension of a 3d grid :ul
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[Examples:]
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processors 2 4 4 :pre
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[Description:]
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Specify how processors are mapped as a 3d logical grid to the global
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simulation box.
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When this command has not been specified, LAMMPS will choose Px, Py,
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Pz based on the dimensions of the global simulation box so as to
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minimize the surface/volume ratio of each processor's sub-domain.
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Since LAMMPS does not load-balance by changing the grid of 3d
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processors on-the-fly, this command should be used to override the
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LAMMPS default if it is known to be sub-optimal for a particular
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problem. For example, a problem where the atom's extent will change
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dramatically over the course of the simulation.
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The product of Px, Py, Pz must equal P, the total # of processors
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LAMMPS is running on. If multiple partitions are being used then P is
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the number of processors in this partition; see "this
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2007-02-10 05:37:30 +08:00
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section"_Section_start.html#2_6 for an explanation of the -partition
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2006-09-22 00:22:34 +08:00
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command-line switch.
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If P is large and prime, a grid such as 1 x P x 1 will be required,
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which may incur extra communication costs.
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[Restrictions:]
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This command cannot be used after the simulation box is defined by a
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"read_data"_read_data.html or "create_box"_create_box.html command.
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It can be used before a restart file is read to change the 3d
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processor grid from what is specified in the restart file.
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[Related commands:] none
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[Default:]
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LAMMPS chooses Px, Py, Pz
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