g_nmens(1) generates an ensemble of structures from the normal modes


g_nmens -v eigenvec.trr -e eigenval.xvg -s topol.tpr -n index.ndx -o ensemble.xtc -[no]h -[no]version -nice int -xvg enum -temp real -seed int -num int -first int -last int


g_nmens generates an ensemble around an average structure in a subspace that is defined by a set of normal modes (eigenvectors). The eigenvectors are assumed to be mass-weighted. The position along each eigenvector is randomly taken from a Gaussian distribution with variance kT/eigenvalue.

By default the starting eigenvector is set to 7, since the first six normal modes are the translational and rotational degrees of freedom.


-v eigenvec.trr Input
 Full precision trajectory: trr trj cpt 

-e eigenval.xvg Input
 xvgr/xmgr file 

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

-n index.ndx Input, Opt.
 Index file 

-o ensemble.xtc Output
 Trajectory: xtc trr trj gro g96 pdb 


 Print help info and quit

 Print version info and quit

-nice int 19
 Set the nicelevel

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

-temp real 300
 Temperature in Kelvin

-seed int -1
 Random seed, -1 generates a seed from time and pid

-num int 100
 Number of structures to generate

-first int 7
 First eigenvector to use (-1 is select)

-last int -1
 Last eigenvector to use (-1 is till the last)