AMBER Archive (2008)

Subject: Re: AMBER: NAB conjgrad returns error?

From: David A. Case (
Date: Mon Aug 11 2008 - 16:40:49 CDT

On Mon, Aug 11, 2008, Carra, Claudio (JSC-SK)[USRA] wrote:

> thanks a lot for your help, however, I still have some problems
> with the corrected sff2.c file. The job ends but the structure is
> not optimized and the thresholds are not reached.

You generally cannot start newton-raphson minimizations until you are at
a pretty low rms gradient, say 10**-5 or better. You many need to run
*lots* of conjugate gradient steps before switching over, and set a
much lower target rms gradient.


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