GMX-GYRATE(1)

NAME
gmx-gyrate - Calculate radius of gyration of a molecule

SYNOPSIS

    gmx gyrate [-f [<.xtc/.trr/...>]] [-s [<.tpr/.gro/...>]] [-n [<.ndx>]]
               [-o [<.xvg>]] [-b <time>] [-e <time>] [-dt <time>]
               [-tu <enum>] [-fgroup <selection>] [-xvg <enum>]
               [-[no]rmpbc] [-sf <file>] [-selrpos <enum>]
               [-seltype <enum>] [-sel <selection>] [-mode <enum>]

DESCRIPTION

gmx gyrate computes the radius of gyration of a molecule and the radii of gyration about the x-, y- and z-axes, as a function of time. The atoms are explicitly mass weighted.

The axis components corresponds to the mass-weighted root-mean-square of the radii components orthogonal to each axis, for example:

Rg(x) = sqrt((sum_i w_i (R_i(y)^2 + R_i(z)^2))/(sum_i w_i)).

where w_i is the weight value in the given situation (mass, charge, unit)

Note that this is a new implementation of the gyrate utility added in GROMACS 2024. If you need the old one, use gmx gyrate-legacy.

OPTIONS

Options to specify input files:

-f [<.xtc/.trr/...>] (traj.xtc) (Optional)
    Input trajectory or single configuration: xtc trr cpt gro g96 pdb tng h5md

-s [<.tpr/.gro/...>] (topol.tpr) (Optional)
    Input structure: tpr gro g96 pdb brk ent

-n [<.ndx>] (index.ndx) (Optional)
    Extra index groups

    Options to specify output files:

-o [<.xvg>] (gyrate-taf.xvg)
    Filename for gyrate plot output

    Other options:

-b <time> (0)
    First frame (ps) to read from trajectory

-e <time> (0)
    Last frame (ps) to read from trajectory

-dt <time> (0)
    Only use frame if t MOD dt == first time (ps)

-tu <enum> (ps)
    Unit for time values: fs, ps, ns, us, ms, s

-fgroup <selection>
    Atoms stored in the trajectory file (if not set, assume first N atoms)

-xvg <enum> (xmgrace)
    Plot formatting: xmgrace, xmgr, none

-[no]rmpbc (yes)
    Make molecules whole for each frame

-sf <file>
    Provide selections from files

-selrpos <enum> (atom)
    Selection reference positions: atom, res_com, res_cog, mol_com, mol_cog, whole_res_com, whole_res_cog, whole_mol_com, whole_mol_cog, part_res_com, part_res_cog, part_mol_com, part_mol_cog, dyn_res_com, dyn_res_cog, dyn_mol_com, dyn_mol_cog

-seltype <enum> (atom)
    Default selection output positions: atom, res_com, res_cog, mol_com, mol_cog, whole_res_com, whole_res_cog, whole_mol_com, whole_mol_cog, part_res_com, part_res_cog, part_mol_com, part_mol_cog, dyn_res_com, dyn_res_cog, dyn_mol_com, dyn_mol_cog

-sel <selection>
    Select group to compute gyrate radius

-mode <enum> (mass)
    Atom weighting mode: mass, charge, geometry

SEE ALSO

gmx(1)

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