g_genrestr (1) - Linux Manuals

g_genrestr: generates position restraints or distance restraints for index groups


genrestr - generates position restraints or distance restraints for index groups



genrestr -f conf.gro -n index.ndx -o posre.itp -of freeze.ndx -[no]h -nice int -fc vector -freeze real -[no]disre -disre_dist real -disre_frac real -disre_up2 real -[no]constr


genrestr produces an include file for a topology containing a list of atom numbers and three force constants for the X, Y and Z direction. A single isotropic force constant may be given on the command line instead of three components.

WARNING: position restraints only work for the one molecule at a time. Position restraints are interactions within molecules, therefore they should be included within the correct [ moleculetype ] block in the topology. Since the atom numbers in every moleculetype in the topology start at 1 and the numbers in the input file for genpr number consecutively from 1, genpr will only produce a useful file for the first molecule.

The -of option produces an index file that can be used for freezing atoms. In this case the input file must be a pdb file.

With the -disre option half a matrix of distance restraints is generated instead of position restraints. With this matrix, that one typically would apply to C-alpha atoms in a protein, one can maintain the overall conformation of a protein without tieing it to a specific position (as with position restraints).


-f conf.gro Input
 Structure file: gro g96 pdb tpr tpb tpa 

-n index.ndx Input, Opt.
 Index file 

-o posre.itp Output
 Include file for topology 

-of freeze.ndx Output, Opt.
 Index file 


 Print help info and quit

-nice int 0
 Set the nicelevel

-fc vector 1000 1000 1000
 force constants (kJ mol-1 nm-2)

-freeze real 0
 if the -of option or this one is given an index file will be written containing atom numbers of all atoms that have a B-factor less than the level given here

 Generate a distance restraint matrix for all the atoms in index

-disre_dist real 0.1
 Distance range around the actual distance for generating distance restraints

-disre_frac real 0
 Fraction of distance to be used as interval rather than a fixed distance. If the fraction of the distance that you specify here is less than the distance given in the previous option, that one is used instead.

-disre_up2 real 1
 Distance between upper bound for distance restraints, and the distance at which the force becomes constant (see manual)

 Generate a constraint matrix rather than distance restraints



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