# compute smd/ulsph/num/neighs command

## Syntax

compute ID group-ID smd/ulsph/num/neighs

• ID, group-ID are documented in compute command

• smd/ulsph/num/neighs = style name of this compute command

## Examples

compute 1 all smd/ulsph/num/neighs


## Description

Define a computation that returns the number of neighbor particles inside of the smoothing kernel radius for particles interacting via the updated Lagrangian SPH pair style.

See this PDF guide to using Smooth Mach Dynamics in LAMMPS.

## Output info

This compute returns 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 doc page for an overview of LAMMPS output options.

The per-particle values will be given dimensionless, see units.

## Restrictions

This compute is part of the USER-SMD package. It is only enabled if LAMMPS was built with that package. See the Build package doc page for more info. This compute can only be used for particles which interact with the updated Lagrangian SPH pair style.

none