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### fix gyration command

Syntax:

    fix ID group-ID gyration N file

- ID, group-ID are documented in fix command
- gyration = style name of this fix command
- N = compute radius-of-gyration every this many timesteps
- file = filename to write gyration info to

Examples:

    fix 1 all gyration 100 molecule.out

Description:

Compute the radius-of-gyration of the group of atoms every N steps, including all effects due to atoms passing thru periodic boundaries. Write the results to the specified file.

Rg is a measure of the size of the group of atoms, and is computed by this formula

where M is the total mass of the group and Rcm is the center-of-mass position of the group.

Restart, fix_modify, output, run start/stop, minimize info:

No information about this fix is written to binary restart files. None of the fix_modify options are relevant to this fix. No global scalar or vector or per-atom quantities are stored by this fix for access by various output commands. No parameter of this fix can be used with the start/stop keywords of the run command. This fix is not invoked during energy minimization.

Restrictions: none

Related commands: none

Default: none