From chemistry-request "-at-" server.ccl.net Wed Feb 7 01:21:45 2001 Received: from ksmail.netcologne.de (ksmail.netcologne.de [194.8.194.97]) by server.ccl.net (8.11.0/8.11.0) with ESMTP id f176Liw28984 for ; Wed, 7 Feb 2001 01:21:44 -0500 Received: from cosmologic.de (dial-213-168-88-201.netcologne.de [213.168.88.201]) by ksmail.netcologne.de (8.9.3/8.9.3) with ESMTP id HAA05096; Wed, 7 Feb 2001 07:21:39 +0100 (MET) Message-ID: <3A80E9BD.F15D1159 $#at#$ cosmologic.de> Date: Wed, 07 Feb 2001 07:22:53 +0100 From: "Dr. Andreas Klamt" Organization: COSMOlogic GmbH&CoKG X-Mailer: Mozilla 4.7 [de] (Win98; I) X-Accept-Language: en,pdf MIME-Version: 1.0 To: Olegas Eicher-Lorka , chemistry ^%at%^ ccl.net Subject: Re: CCL:Gaussian Raman Intensities in Solution References: <000e01c08f7b$4d114260$ae0e3bd4 ^%at%^ ktl.mii.lt.lorka.ktl.mii.lt> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Although I am not familiar with the details of the COSMO implementation in Gaussian, being the author of the original COSMO I like to shortly comment on the general question of Raman intensities in solution: Note, that high vibrational frequencies in solution are definitely not in equilibrium with the reorientational part of the solvent polarization. Therefore calculation of second derivatives of the total energy are not adequate for vibrational frequencies. The best way to calculate the Raman frequencies in solution would be - to first do geometry optimization in the solvent - then freeze the polarization charges - do second derivatives while treating the (molecule + frozen equilibrium polarization charges) as embedded in a medium of electronic polarizability (eps=2). I am not sure, whether such treatment is possible in Gaussian, but it efinitely would be the physically most correct way to do it. Andreas Klamt -------------------------------------------------------------------------------- Dr. Andreas Klamt COSMOlogic GmbH&CoKG Burscheider Str. 515 51381 Leverkusen, Germany Tel.: 49-2171-73168-1 Fax: ...-9 e-mail: andreas.klamt \\at// cosmologic.de web: www.cosmologic.de -------------------------------------------------------------------------------- COSMOlogic Your Competent Partner for Computational Chemistry and Fluid Thermodynamics --------------------------------------------------------------------------------