AMBER Archive (2004)

Subject: Re: AMBER: resp error message

From: FyD (
Date: Wed Sep 29 2004 - 14:55:26 CDT

> I'm using resp to generate the atomic charges of an
> organic molecule but I'm getting the following error
> message:
> Number of unique UNfrozen centers= 106
> Non-linear optimization requested.
> chgopt: LU decomp gave almost-singular U

I got the same problem. If you use several molecular orientations try to
decrease the number of orientations... It is related to the number of
restraints you use in your input1... Francois
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