From owner-chemistry@ccl.net Fri Dec 21 00:07:00 2007
From: "N Venkataramanan S venkataramananns_+_gmail.com" <owner-chemistry::server.ccl.net>
To: CCL
Subject: CCL:G: Optmizing adduct complex
Message-Id: <-35899-071220234009-12214-2Qergr/O4i9bYJNCuk4H3w::server.ccl.net>
X-Original-From: "N Venkataramanan S" <venkataramananns{:}gmail.com>
Date: Thu, 20 Dec 2007 23:40:05 -0500


Sent to CCL by: "N Venkataramanan S" [venkataramananns],[gmail.com]
Dear CCL users

I am trying to optmize a structure involving a adduct like reactant complex (Fe (OXO) complex + Organic substrate). When i try to optimize the system  with opt keyword the organic substrate keeps on moving from initial distance of 2.5 to 13 amstrong distance without converging(even after 75 opt cycles). When using opt=(TS) the same problem occurs. In liteature, I saw some reports on similar systems that the distance between the oxo and hydrogen of the substrates were about 2 to 2.5. I am using Gaussain G03

(references : J. Phys. Chem. C 2007, 111, 12397-12406, J. Am. Chem. Soc. 2006, 128, 8590-8606)

Please suggest me some method to solve the problem.

With thanks in advance
Sincerely
Venkataramanan