# comm_style command

## Syntax

``` LAMMPS
comm_style style
```

-   style = *brick* or *tiled*

## Examples

``` LAMMPS
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 [balance](balance) or [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 partitioning 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) or
[read_data](read_data) or [read_restart](read_restart) commands. For
both the *brick* and *tiled* styles, the initial decomposition will be
the same, as described by [create_box](create_box) and
[processors](processors) commands. The decomposition can be changed via
the [balance](balance) or [fix balance](fix_balance) commands.

## Restrictions

None

## Related commands

[comm_modify](comm_modify), [processors](processors),
[balance](balance), [fix balance](fix_balance)

## Default

The default style is brick.