From chemistry-request@server.ccl.net Sun Aug 4 13:52:28 2002 Received: from as1200.organik.uni-erlangen.de ([131.188.128.6]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g74HqRl02801 for ; Sun, 4 Aug 2002 13:52:28 -0400 Received: from ccc.uni-erlangen.de (temeraire.chemie.uni-erlangen.de [131.188.128.73]) by as1200.organik.uni-erlangen.de (8.8.7/8.1.11-FAU) with ESMTP id TAA02111 for ; Sun, 4 Aug 2002 19:52:26 +0200 (MET DST) Sender: Anselm.Horn@Organik.Uni-Erlangen.DE Message-ID: <3D4D63AD.9E9E59A4@ccc.uni-erlangen.de> Date: Sun, 04 Aug 2002 19:26:05 +0200 From: Anselm Horn Organization: CCC X-Mailer: Mozilla 4.78 [en] (X11; U; OSF1 V5.0 alpha) X-Accept-Language: en MIME-Version: 1.0 To: chemistry@ccl.net Subject: Hessian for Sybyl out-of-plain potential Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Dear all, I am looking for the analytical expression of the Hessian matrix (with respect to cartesian coordinates of atoms A, B, C. D) for the Tripos (Sybyl) force field type out-of-plain potential: E(oop) = k*(h - h0)**2, where h is the distance from atom A to the plain formed by atoms B, C, and D; k is the force constant and h0 is a possible "optimum" distance. Any kind of hint (Journal reference, web page, program source code etc) would be very helpful! Thanks in advance, Anselm -- _______________________________________________________________________ Anselm Horn, Dipl. Chem. Univ. Anselm.Horn@ccc.uni-erlangen.de ___ / __| ___ Computer Chemie Centrum | / ___ / __| | | / __|| / Naegelsbachstrasse 25 \ \__ | / | | D-91025 Erlangen \___|| | \ \__ Deutschland / Germany \ \__ \___| Tel: +49 9131/85-2-6583 * Fax: +49 9131/85-2-6565 \___| http://www.ccc.uni-erlangen.de/clark/horn/index.html _______________________________________________________________________