RE: AMBER: switching function for electrostatic interactions

From: Ross Walker <>
Date: Mon, 12 Jun 2006 08:28:19 -0700

Dear Fabien,

> I am a little confused about which type of cut-off is used by
> sander or pmemd
> when computing electrostatic interactions with PME.
> I first thought that it was a sharp cut-off as is the case
> for van der Waals
> interactions, but in the manual, I read that a cubic spline switching
> function is used. I have tried to find an answer in the
> mailing list and in
> the FAQ but did not find it (or did not understand), so I
> apologize if this
> question has already been answered some time ago.

A sharp cut off is used but this is then adjusted for Erfc and it is the
calculation of this that EEDMETH is refering to. You cannot simply use a
sharp cut off when doing PME. Refer to T. Darden, D. York, L. Pedersen, J
Chem Phys, 98, 10089-10092 (1993).

All the best

|\oss Walker

| HPC Consultant and Staff Scientist |
| San Diego Supercomputer Center |
| Tel: +1 858 822 0854 | EMail:- |
| | PGP Key available on request |

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Received on Wed Jun 14 2006 - 06:07:11 PDT
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