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### compute event/displace command

Syntax:

    compute ID group-ID event/displace threshold

- ID, group-ID are documented in compute command
- event/displace = style name of this compute command
- threshold = minimum distance anyparticle must move to trigger an event (distance units)

Examples:

    compute 1 all event/displace 0.5

Description:

Define a computation that flags an "event" if any particle in the group has moved a distance greater than the specified threshold distance when compared to a previously stored reference state (i.e. the previous event). This compute is typically used in conjunction with the prd command, to detect if a transition to a new minimum energy basin has occurred.

This value calculated by the compute is equal to 0 if no particle has moved far enough, and equal to 1 if one or more particles have moved further than the threshold distance.

Output info:

This compute calculates a global scalar (the flag). This value can be used by any command that uses a global scalar value from a compute as input. See this section for an overview of LAMMPS output options.

The scalar value calculated by this compute is "intensive". The scalar value will be a 0 or 1 as explained above.

Restrictions:

This command can only be used if LAMMPS was built with the "prd" package. See the Making LAMMPS section for more info on packages.

Related commands:

prd

Default: none