AMBER Archive (2006)

Subject: Re: AMBER: Question bonds and angles in frcmod and lib files

From: Bill Ross (
Date: Wed May 03 2006 - 11:28:08 CDT

> > I'm trying to more completely understand the information contained in
> > frcmod and lib files. I would like to change from using an angle to
> > constrain the geometry of my molecule to using an artificial bond with a
> > given force constant. I understand how to add a bond to both the lib
> > file and to the frcmod file. However, I don't understand how to delete
> > an angle from these files.
> Generally, you effectively delete the angle term by (re-)defining that angle
> potential with a force constant of zero.

Be sure when modifying params that you intend to modify all instances
of the atom types involved.

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