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lammps/doc/_sources/comm_style.txt
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comm_style.txt
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.. index:: comm_style
comm_style command
==================
Syntax
""""""
.. parsed-literal::
comm_style style
* style = *brick* or *tiled*
Examples
""""""""
.. parsed-literal::
comm_style brick
comm_style tiled
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 :doc:`balance <balance>` or :doc:`fix balance <fix_balance>` 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 :doc:`create_box <create_box>`
or :doc:`read_data <read_data>` or :doc:`read_restart <read_restart>`
commands. For both the *brick* and *tiled* styles, the initial
decomposition will be the same, as described by
:doc:`create_box <create_box>` and :doc:`processors <processors>`
commands. The decomposition can be changed via the
:doc:`balance <balance>` or :doc:`fix_balance <fix_balance>` commands.
Restrictions
""""""""""""
none
Related commands
""""""""""""""""
:doc:`comm_modify <comm_modify>`, :doc:`processors <processors>`,
:doc:`balance <balance>`, :doc:`fix balance <fix_balance>`
Default
"""""""
The default style is brick.
.. _lws: http://lammps.sandia.gov
.. _ld: Manual.html
.. _lc: Section_commands.html#comm
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