g_bond(1) - Linux man page

Name

g_bond - calculates distances between atoms

VERSION 4.5.4-dev-20110404-bc5695c

Synopsis

g_bond -f traj.xtc -n index.ndx -s topol.tpr -o bonds.xvg -l bonds.log -d distance.xvg -[no]h -[no]version -nice int -b time -e time -dt time -[no]w -xvg enum -blen real -tol real -[no]aver -[no]averdist

Description

g_bond makes a distribution of bond lengths. If all is well a Gaussian distribution should be made when using a harmonic potential. Bonds are read from a single group in the index file in order i1-j1 i2-j2 through in-jn.

-tol gives the half-width of the distribution as a fraction of the bondlength ( -blen). That means, for a bond of 0.2 a tol of 0.1 gives a distribution from 0.18 to 0.22.

Option -d plots all the distances as a function of time. This requires a structure file for the atom and residue names in the output. If however the option -averdist is given (as well or separately) the average bond length is plotted instead.

Files

-f traj.xtc Input Trajectory: xtc trr trj gro g96 pdb cpt

-n index.ndx Input Index file

-s topol.tpr Input, Opt. Structure+mass(db): tpr tpb tpa gro g96 pdb

-o bonds.xvg Output xvgr/xmgr file

-l bonds.log Output, Opt. Log file

-d distance.xvg Output, Opt. xvgr/xmgr file

Other Options

-[no]hno Print help info and quit

-[no]versionno Print version info and quit

-nice int 19 Set the nicelevel

-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 when t MOD dt = first time (ps)

-[no]wno View output .xvg, .xpm, .eps and .pdb files

-xvg enum xmgrace xvg plot formatting: xmgrace, xmgr or none

-blen real -1 Bond length. By default length of first bond

-tol real 0.1 Half width of distribution as fraction of blen

-[no]averyes Average bond length distributions

-[no]averdistyes Average distances (turns on -d)

Known Problems

- It should be possible to get bond information from the topology.

See Also

gromacs(7)

More information about GROMACS is available at <http://www.gromacs.org/>.