"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c

:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)

:line

comm_style command :h3

[Syntax:]

comm_style style :pre

style = {brick} or {tiled} :ul

[Examples:]

comm_style brick
comm_style tiled :pre

[Description:]

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.

For the default {brick} 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.

For the {tiled} style, a more general domain decomposition can be
used, as triggered by the "balance"_balance.html or "fix
balance"_fix_balance.html 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.

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 "create_box"_create_box.html
or "read_data"_read_data.html or "read_restart"_read_restart.html
commands.  For both the {brick} and {tiled} styles, the initial
decomposition will be the same, as described by
"create_box"_create_box.html and "processors"_processors.html
commands.  The decomposition can be changed via the
"balance"_balance.html or "fix balance"_fix_balance.html commands.

[Restrictions:] none

[Related commands:]

"comm_modify"_comm_modify.html, "processors"_processors.html,
"balance"_balance.html, "fix balance"_fix_balance.html

[Default:]

The default style is brick.
