"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c

:link(lws,http://lammps.sandia.gov)
:link(ld,Manual.html)
:link(lc,Section_commands.html#comm)

:line

fix gyration command :h3

[Syntax:]

fix ID group-ID gyration N file :pre

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

[Examples:]

fix 1 all gyration 100 molecule.out :pre

[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

:c,image(Eqs/fix_gyration.jpg)

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"_restart.html.  None of the "fix_modify"_fix_modify.html 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"_Section_howto.html#4_15.  No parameter of this fix can be
used with the {start/stop} keywords of the "run"_run.html command.
This fix is not invoked during "energy minimization"_minimize.html.

[Restrictions:] none

[Related commands:] none

[Default:] none
