AMBER Archive (2000)

Subject: Re: frcmod file format in amber 6.0

From: Bill Ross (ross_at_cgl.ucsf.edu)
Date: Wed Dec 13 2000 - 11:57:27 CST


Regular parm.dat files can be used instead of frcmod files
in leap, however since the format is less intuitive, there
is greater potential for human error.

http://www.amber.ucsf.edu/amber/formats.html#frcmod

Bill Ross

        I am confused about the frcmod file which allows to modify the force
        field parameters.
        In Amber 4.1 this was done via the parm program. The parm documentation
        gives a description of the
        frcmod file format which differs from the parm9x.dat files (for instance
        the keywords MASS, BOND, ...)
        
        In amber 6.0 both parm94.dat and frcmod files are loaded via the same
        leap command
        
        parm94 = loadamberparams parm94.dat
        frcmod = loadamberparams frcmod.pcy
        
        (see tutorial p 22)
        
        but the format of both files seems to be different.
        
        I do not find the format of the frcmod files in the amber 6.0
        documentation.
        Can I use the format of a parm9x.dat file to modify the parameters ?
        
        
        thanks a lot for your help
        mathy froeyen