Re: AMBER: gaff: ca-ca-c -o torsion parameter

From: David A. Case <>
Date: Tue, 17 May 2005 23:38:33 -0700

On Tue, May 17, 2005, Oliver Hucke wrote:
> My conclusion is that the following line should be added to the gaff
> force field to get a barrier of 4kcal/mol:
> ca-ca-c -o 1 .5 180.0 2.0

Clearly, you should try this out, rotate your molecule about the ca-c torsion,
and see what barrier you get. The actual barriers include non-bonded and
electrostatic terms, as well as the intrinsic barrier. Assuming(!) that your
4kcal target is correct, you need to carry out actual calculations to see what
torsional parameters are required.


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Received on Wed May 18 2005 - 07:53:01 PDT
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