From chemistry-request@ccl.net Mon Apr 19 10:45:11 2004 Received: from mail2.atl.registeredsite.com (mail2.atl.registeredsite.com [64.224.219.76]) by server.ccl.net (8.12.8/8.12.8) with ESMTP id i3JFjAuR000459 for ; Mon, 19 Apr 2004 10:45:10 -0500 Received: from imta01a2.registeredsite.com (imta01a2.registeredsite.com [64.225.255.10]) by mail2.atl.registeredsite.com (8.12.8/8.12.8) with ESMTP id i3JFjqLM027188; Mon, 19 Apr 2004 15:45:52 GMT Received: from [128.230.29.245] by imta01a2.registeredsite.com with ESMTP id <20040419154552.UVVJ3344.imta01a2.registeredsite.com@[128.230.29.245]>; Mon, 19 Apr 2004 11:45:52 -0400 In-Reply-To: <4083D3EE.2000309(at)college-de-france.fr> References: <4083D3EE.2000309(at)college-de-france.fr> Mime-Version: 1.0 (Apple Message framework v613) Content-Type: text/plain; charset=ISO-8859-1; format=flowed Message-Id: Cc: Damian Gregory Allis From: Damian Gregory Allis Subject: Re: CCL:DNP in DMol <--> 6-31G** in Gaussian? Date: Mon, 19 Apr 2004 11:45:52 -0400 To: Nicolas Saettel , chemistry(at)ccl.net X-Mailer: Apple Mail (2.613) 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 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by server.ccl.net id i3JFjBuR000463 Greetings, Nicolas I've had quite a bit of experience using DMol3 (at NCSA) and GGA functionals for calculating inelastic neutron scattering spectra and examining the deformation of rigid molecules in the solid-state, which also means doing side-by-side DMol3 and Gaussian/GAMESS comparisons of isolated molecules for structural comparisons. Generally speaking, dnp and 6-31G** (as reported in the Delley papers as well) line up the best from among all available choices. That said, I've not had an experience yet where the DMol3 geometries were closer to crystallographic distances than the Gaussian/GAMESS jobs. The standard molecular treatments of the "familiar" atom-centered QC packages simply do a better job of getting the structure right in the 7 or so systems I've worked on, so be less concerned with the DMol v.s. Gaussian/GAMESS structures and more concerned with those same comparisons to any structural data you have. The DMol3 normal mode calculations, however, do a phenomenal job of reproducing the vibrational spectra and intensities in the INS work despite having slightly worse geometries. For a useful geometry comparison, I direct you to the pagodane paper below. The BH4 paper below is biased towards frequencies only but provides another useful comparison. Unfortunately, I've not played around much with the LDA functionals, so can't provide any useful info about differences you'll see there. Allis D.G., Prinzbach H., and Hudson B.S. "Inelastic Neutron Scattering Spectra of Pagodane: Experiment and DFT Calculations." Chemical Physics Letters, 386 (2004) 356-363. Allis D.G. and Hudson B.S. "Inelastic Neutron Scattering Spectra of NaBH4 and KBH4: Reproduction of Anion Mode Shifts via Periodic DFT." Chemical Physics Letters, 385 (2004) 166-172. cheers, Damian On Apr 19, 2004, at 9:28 AM, Nicolas Saettel wrote: > Hi all, > I would like to reproduce LDA calculations that were done using the > double numerical basis set with polarization functions in DMol (DNP). > Am I correct in using SVWN/6-31G** in Gaussian? > Thank you in advance > Nicolas Saettel > > > -- > Nicolas Saettel, Ph.D. http://nicolas.saettel.free.fr > Laboratoire de Chimie des Interactions Moliculaires > CNRS UPR 285 - Collhge de France > http://www.college-de-france.fr/chaires/chaire10/index.htm 11, Place > Marcelin Berthelot - 75005 PARIS > Tel.: 01.44.27.13.63 FAX.: 01.44.27.13.56 > #8^(=)+< p.s. Damian apologizes for the delay. Locale : www.somewhereville.com Delivery : damian(at)somewhereville.com AOL IM : swville "You don't need money to be rich anyhow. Spending yourself is what it's all about." -Marillion, "Rich"