AMBER Archive (2000)

Subject: Gibbs / Torcon problem

From: Terreux Raphael (terreux_at_taloa.unice.fr)
Date: Mon Sep 04 2000 - 12:53:58 CDT

Dear Amber user,

    I try to compute the free energy between two RNA loops with gibbs. I
use gibbs module with FEP
and i use geometrical constraint between selected atoms and dummy atom
to separate the two RNA.
The simulation run to 0.12 Lambda and the torcon routine crash. The
change request of the constraint is about .0976 Angstom. The error
message is :
------------------------------------
Routine TORCON (internal constraints) failed
     to converge within 1000 iterations.
------------------------------------

Does anybody have sugestion ? may be to increase the number of
interation but how ?
use CMC/MD rather than gibbs ?

Thanks for your help
Best regards

Raphael Terreux 

--
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TERREUX Raphael

Laboratoire A.S.I Equipe Chimiometrie Modelisation
Universite de Nice-Sophia Antipolis,
Parc Valrose, F 06108, Cedex 2,
NICE, FRANCE

TEL : +33 (0)4 92 07 61 26
FAX : +33 (0)4 92 07 61 25
e-mail : terreux_at_chiminfo.unice.fr
         terreux_at_unice.fr
web    : http://chiminfo11.unice.fr/~terreux/index.htm
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