AMBER Archive (2006)

Subject: Re: AMBER: second derivative matrix

From: David A. Case (
Date: Tue Jun 20 2006 - 16:37:01 CDT

On Tue, Jun 20, 2006, Marie Brut wrote:
> The matter is I am very
> surprised by the second derivative matrix (named ddr) size : 6 lines by 6
> columns ! It seems to be really weak for an Hessian matrix, isn't it?

ddr() is just the Hessian matrix for a single pair interaction, giving the
second derivatives of that term with respect to the Cartesian coordinates of
the two atoms involved. These items are later inserted into the "full"
Hessian matrix.


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