g_velacc(1) - Linux man page
Name
g_velacc - calculates velocity autocorrelation functionsVERSION 4.5.4-dev-20110404-bc5695c
Synopsis
Description
g_velacc computes the velocity autocorrelation function. When the -m option is used, the momentum autocorrelation function is calculated.With option -mol the velocity autocorrelation function of molecules is calculated. In this case the index group should consist of molecule numbers instead of atom numbers.
Files
-f traj.trr Input Full precision trajectory: trr trj cpt-s topol.tpr Input, Opt. Structure+mass(db): tpr tpb tpa gro g96 pdb
-n index.ndx Input, Opt. Index file
-o vac.xvg Output 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
-[no]mno Calculate the momentum autocorrelation function
-[no]molno Calculate the velocity acf of molecules
-acflen int -1 Length of the ACF, default is half the number of frames
-[no]normalizeyes Normalize ACF
-P enum 0 Order of Legendre polynomial for ACF (0 indicates none): 0, 1, 2 or 3
-fitfn enum none Fit function: none, exp, aexp, exp_exp, vac, exp5, exp7, exp9 or erffit
-ncskip int 0 Skip N points in the output file of correlation functions
-beginfit real 0 Time where to begin the exponential fit of the correlation function
-endfit real -1 Time where to end the exponential fit of the correlation function, -1 is until the end
See Also
gromacs(7)More information about GROMACS is available at <http://www.gromacs.org/>.