From chemistry-request@ccl.net Thu Nov 6 10:31:09 2003 Received: from sungoddess.ccs.yorku.ca (sungoddess.ccs.yorku.ca [130.63.236.144]) by server.ccl.net (8.12.8/8.12.8) with ESMTP id hA6FUbVc011007 for ; Thu, 6 Nov 2003 10:30:37 -0500 Received: from mountain.chem.yorku.ca (mountain.chem.yorku.ca [130.63.133.28]) by sungoddess.ccs.yorku.ca (8.12.10/8.12.8) with SMTP id hA6FUWcq000984; Thu, 6 Nov 2003 10:30:36 -0500 (EST) Date: Thu, 6 Nov 2003 10:17:03 -0500 (EST) From: Rene Fournier - 1999-07-07 X-Sender: renef!at!mountain.chem.yorku.ca To: Mikael Johansson cc: Steve Williams , CHEMISTRY!at!ccl.net Subject: Re: CCL:fractional nuclear charge In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Status: No, hits=-0.5 required=7.0 tests=IN_REP_TO,USER_AGENT_PINE version=2.55 X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp) Hello Steve, Mikael, Everyone: As Mikael wrote, with fractional nuclear charges... >The basis set might be a problem, as they are optimised for specific >atoms. I totally agree. >I guess one way of getting around this would be to use a combined >basis set for the metamorphosing atom, consisting of the BS of both >the initial (O) and the final (N) atoms. I am afraid this might give problems with near linear dependencies, maybe inacurrate inversion of the overlap matrix. A way around that problem would be to define an "intermediate basis set" by interpolating two (preferably large) O and N basis sets that have the same contraction pattern, ie, a "metamorphosing basis set for a metamorphosing atom". I have a related question: does anyone know of a program that would allow to use positive charge distributions other than a set of point charges, for instance, a set of spherical Gaussian distributions. -- Rene ------------------------------------------ | Rene Fournier, Associate Professor | | Chemistry Dpt, York University | | 4700 Keele Street, Toronto | | Ontario, CANADA M3J 1P3 | ------------------------------------------