From chemistry-request@server.ccl.net Fri Mar 8 12:58:17 2002 Received: from tigre ([158.109.14.43]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g28HwF516464 for ; Fri, 8 Mar 2002 12:58:16 -0500 Received: from gali by tigre with local (Exim 3.12 #1 (Debian)) id 16jOc3-0003ah-00 for ; Fri, 08 Mar 2002 18:57:03 +0100 Date: Fri, 8 Mar 2002 18:57:03 +0100 From: Gali Drudis i Sole To: CCL Subject: ONIOM DFT/AM1 calculations with Osmium Message-ID: <20020308185703.A13746@tigre.qf.uab.es> Mail-Followup-To: CCL Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.2.5i Sender: Debian User I am trying to calculate a large molecule using a hybrid method. The molecule contains an osmium tetroxide plus a large organic residue. The procedure will involve an ONIOM calculation using a small DFT region plus a large semiempiric region. However, the ONIOM method requires that the whole molecule be described by the low method, AM1 in this case. The problem arises when I try to calculate the whole molecule using AM1. To my unluck, not only is Osmium not parametrized in Gaussian98.A9, but the VSTO-3G basis does not suppor athoms greater than N=54 (osmium has an atomic number of 76). To make things worse, looking inside the code, every athom with N>54 is exchanged by Xe in link 301. But Xenon is described without d orbitals, and therefore I get the following error: ======================================================================== (Enter /QFsoft/g98/l301.exe) Standard basis: VSTO-3G (5D, 7F) Atomic number 76 exceeds maximum of 54 in STO -- maximum used. There are 5 symmetry adapted basis functions of A' symmetry. There are 1 symmetry adapted basis functions of A" symmetry. Crude estimate of integral set expansion from redundant integrals=1.000. Integral buffers will be 262144 words long. Raffenetti 1 integral format. Two-electron integral symmetry is turned on. 6 basis functions 18 primitive gaussians 5 alpha electrons 5 beta electrons nuclear repulsion energy 5.0493269225 Hartrees. Leave Link 301 at Fri Mar 8 18:49:55 2002, MaxMem= 6291456 cpu: 0.1 (Enter /QFsoft/g98/l401.exe) Simple Huckel Guess. NBasis= 6 NMin= 11 so simple Huckel guess is impossible. Error termination via Lnk1e in /QFsoft/g98/l401.exe. ======================================================================== Link 401 complains that not enough basis functions are available. Do you have any hint how I could solve this problem? Many thanks in advance, -- Galí Drudis i Solé gali@klingon.uab.es Universitat Autònoma de Barcelona Unitat de Química Lab: C7/157 Tel: +34 93-581.28.14 Fax: +34 93-581.29.20