# compute smd/vol command

## Syntax

    compute ID group-ID smd/vol

-   ID, group-ID are documented in [compute](compute) command
-   smd/vol = style name of this compute command

## Examples

``` LAMMPS
compute 1 all smd/vol
```

## Description

Define a computation that provides the per-particle volume and the sum
of the per-particle volumes of the group for which the fix is defined.

See [this PDF guide](PDF/MACHDYN_LAMMPS_userguide.pdf)\_ to using Smooth
Mach Dynamics in LAMMPS.

## Output info

This compute calculates a per-particle vector, which can be accessed by
any command that uses per-particle values from a compute as input. See
the [Howto output](Howto_output) page for an overview of LAMMPS output
options.

The per-particle vector values will be given in [units](units) of
volume.

Additionally, the compute returns a scalar, which is the sum of the
per-particle volumes of the group for which the fix is defined.

## Restrictions

This compute is part of the MACHDYN package. It is only enabled if
LAMMPS was built with that package. See the [Build
package](Build_package) page for more info.

## Related commands

[compute smd/rho](compute_smd_rho)

## Default

none