scaledihedralk

Scale selected dihedral force constants.

scaledihedralk [parm <name> | parmindex <#>] <scale factor> [<mask> [useall]]

Scale dihedral force constants for dihderals selected by <mask> for specified topology.

If useall is specified all atoms in <mask> must be present to select a dihedral, otherwise any atom in <mask> will select a dihedral.