From chemistry-request@ccl.net Fri Mar 11 00:08:48 2005 Received: from smtpout-1.priv.cc.uic.edu (smtpout-1.cc.uic.edu [128.248.155.232]) by server.ccl.net (8.12.8/8.12.8) with SMTP id j2B58luZ005094 for >ccl.net>; Fri, 11 Mar 2005 00:08:47 -0500 Received: (qmail 24098 invoked from network); 10 Mar 2005 22:06:03 -0600 Received: from webmail.cc.uic.edu (HELO webmail.uic.edu) (128.248.121.50) by smtpout-1.cc.uic.edu with SMTP; 10 Mar 2005 22:06:03 -0600 X-WebMail-UserID: ikastr2<>uic.edu Date: Thu, 10 Mar 2005 22:11:25 -0600 Sender: Irida Kastrati >uic.edu> From: Irida Kastrati >uic.edu> To: chemistry<>ccl.net X-EXP32-SerialNo: 50000146 Subject: Locating a Transition State Message-ID: <423799A2<>webmail.uic.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: InterChange (Hydra) SMTP v3.62 X-Spam-Status: No, hits=0.0 required=7.5 tests=none autolearn=no version=2.61 X-Spam-Checker-Version: SpamAssassin 2.61 (1.212.2.1-2003-12-09-exp) on servernd.ccl.net Hello everyone, My name is Irida and I just got involved in some Ab Initio calculations. I am "new" in the field of computational chemistry as well, so I hope you won't mind some obvious questions I have. I am trying to locate a Transition State for the interconversion between two species, that I believe goes through a biradical dissociative mechanism. In the fist trial I located what seemed a TS structure using UHF (Unrestricted, Hartree Fock) with STO-3G as the based set. After Frequency calculations, I found 1 imaginary frequency, thus I thought this might be it. However, once I extend these calculations into DFT methods, the calculations are failing or, > from the frequency calculations I find higher order saddle points. I haven't performed any IRC calculations yet. I would appreciate very much your help and guidance in this matter. Thank you in advance for your time. Sincerely, Irida Kastrati Department of Medicinal Chemistry and Pharmacognosy University of Illinois at Chicago