compute coord/gran command

Syntax

compute ID group-ID coord/gran general_keyword general_values

• ID, group-ID are documented in compute command
• coord/atom = style name of this compute command
• general_keywords general_values are documented in compute

Examples

compute 1 all coord/gran

Description

Define a computation that calculates the coordination number for each atom in a group. The value of the coordination number will be 0.0 for atoms not in the specified compute group.

The coordination number is defined as the number of neighbor atoms within the granular cutoff distance from the central atom. The cutoff distance for granular systems is the sum of the radii of the two particles.

The neighbor list needed to compute this quantity is constructed each time the calculation is performed (i.e. each time a snapshot of atoms is dumped). Thus it can be inefficient to compute/dump this quantity too frequently or to have multiple compute/dump commands, each of a coord/gran style.

Output info

This compute calculates a per-atom vector, which can be accessed by any command that uses per-atom values from a compute as input. See this section for an overview of LIGGGHTS(R)-PUBLIC output options.

The per-atom vector values will be a number >= 0.0, as explained above.

Restrictions

This command cannot be applied to multi-sphere simulations, as the output will not be the per-body coordination number.

Related commands: none

Default: none