From Steve.Bowlus %-% at %-% gwa.sandoz.com Wed Jul 3 11:58:06 1996 Received: from gatekeeper.sandoz.att.nl for Steve.Bowlus %-% at %-% gwa.sandoz.com by www.ccl.net (8.7.5/950822.1) id LAA05818; Wed, 3 Jul 1996 11:05:26 -0400 (EDT) From: Received: by gatekeeper.sandoz.att.nl; id AA19521; Wed, 3 Jul 1996 17:05:25 +0200 X400-Originator: Steve.Bowlus*- at -*gwa.sandoz.com X400-Recipients: CHEMISTRY&$at$&www.ccl.net X400-Mts-Identifier: [/PRMD=SANDOZ/ADMD=400NET/C=CH/;0034700001957191000002] X400-Content-Type: P2-1988 (22) Message-Id: <0034700001957191000002* -x- at -x- MHS> To: Subject: Mopac93: Structure of excited states Date: Wed, 3 Jul 1996 17:07:39 +0200 I am interested in the relative energies and structures of the first excited states (triplet and singlet) of a series of compounds. I have obtained the energies relative to the ground state using the keywords: MECI C.I.=2. I now want to refine the structures of these states, but after 10 cpu-hr on an Indigo2, the gradients are still very large (> 20) and appear to be oscillating. I started the calculation with the optimized ground state structure, and used the keywords: AM1 EF MECI C.I.=2 ROOT=2 (for the triplet, ROOT=3 for the singlet). I have also done the calculation adding SHIFT=15, in an attempt to damp the oscillation. This is my first attempt at working with excited state structures. . .is this typical behavior, and I just need to be patient (sigh!), or have I missed something? If there is interest, I will summarize useful replies, for which I thank the authors in advance. =========================================================================== Stephen B. Bowlus, Ph.D. Computer-Aided Molecular Design Research Division e-mail: bowlus /at\sandoz.com Sandoz Agro, Inc. Phone: + 1 415 354 3904 975 California Ave. Fax: + 1 415 857 1125 Palo Alto, CA 94304 ===========================================================================