AMBER: Re: torsional energy

From: David A. Case <>
Date: Wed, 10 Sep 2003 15:15:34 -0700

On Wed, Sep 10, 2003, kanaga sabai wrote:
> I want to calculate the torsional energy of a given peptide.
> I need only the torsional energy caused by a change in Phi and Psi angles
> around a dipeptide (where the torsion angle is changed) with rest of the
> polypeptide chain kept rigid.

When you change a torsion angle, lots of atoms move, and the nonbonded and
electrosatic energies change, as well as the torsion energy. You probably
just want to generate the new conformation, and calculate its complete force
field energy -- repeating the bonds and angle calculation should cause a
negligible overhead.

...(hope I really understood your question...)....dac

David A. Case                     |  e-mail:
Dept. of Molecular Biology, TPC15 |  fax:          +1-858-784-8896
The Scripps Research Institute    |  phone:        +1-858-784-9768
10550 N. Torrey Pines Rd.         |  home page:                   
La Jolla CA 92037  USA            |
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Received on Wed Sep 10 2003 - 23:53:01 PDT
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