From chemistry-request \\at// server.ccl.net Tue Mar 26 17:31:22 2002 Received: from electra.cc.umanitoba.ca ([130.179.16.23]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g2QMVMp16037 for ; Tue, 26 Mar 2002 17:31:22 -0500 Received: from hultin (hultin.chem.umanitoba.ca [130.179.48.60]) by electra.cc.umanitoba.ca (8.12.2/8.12.2) with SMTP id g2QMVCSu007914 for ; Tue, 26 Mar 2002 16:31:12 -0600 (CST) From: "Phil Hultin" To: "Computational Chemistry List" Subject: Re: Gaussian ONIOM problem Date: Tue, 26 Mar 2002 16:31:12 -0600 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 X-DCC-UofM-Metrics: electra 1032; Body=1 Fuz1=1 Fuz2=1 Martijn Zwijnenburg inquired about the failure of an ONIOM calculation using G98. I just encountered the same problem with my first attempts at using ONIOM. I found that it was necessary to explicitly define the "replace-atom" in the input file for those atoms which were at the boundary between higher and lower levels. The Gaussian manual states that defining a replace-atom is an option, but this apparently is NOT the case. So, Martijn, try modifying your input file to this: %Chk=oniom_test #P trackio # opt ONIOM(B3LYP/sto-3g:AM1) # NoSymm oniom_test job oniom_test archiving 0 1 SI -0.354 -0.184 0.688 High C -1.345 -0.451 -0.882 Medium H F -1.135 -1.670 -1.475 Medium F -2.703 -0.384 -0.701 Medium F -1.082 0.464 -1.870 Medium H -0.901 0.971 1.390 High H 1.037 0.052 0.322 High H -0.466 -1.381 1.514 High Dr. Philip G. Hultin Associate Department Head and Associate Professor of Chemistry University of Manitoba Winnipeg, MB, Canada R3T 2N2 (vox) 204-474-9814 (fax) 204-474-7608 mailto:hultin.,at,.cc.umanitoba.ca http://www.umanitoba.ca/chemistry/