From owner-chemistry@ccl.net Tue May 15 12:23:00 2007 From: "Andreas Klamt klamt_+_cosmologic.de" To: CCL Subject: CCL:G: Gibbs energy with solvent effects Message-Id: <-34269-070515113925-17864-iuomoK6uJKEHqhgfdEyDJw|,|server.ccl.net> X-Original-From: Andreas Klamt Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-15; format=flowed Date: Tue, 15 May 2007 16:45:47 +0200 MIME-Version: 1.0 Sent to CCL by: Andreas Klamt [klamt(!)cosmologic.de] Hi Albert, as I already posted a few times: The vibrational contributions to solvation (at room temperature) are already implicitly aken into account in almost all solvation methods. It does not make any sense to combine them with explicit frequency calculations in the solvent, especially since the latter raise the question whther fast vibrations can be treated by equilibrium solvation. If you are going for Gibbs energies at variable temperature probably my COSMO-RS method (COSMOtherm program) is the only way to go (not just the COSMO-RS keyword in Gaussian!). Best regards Andreas Albert Poater albertpo%%stark.udg.es schrieb: > Sent to CCL by: "Albert Poater" [albertpo:-:stark.udg.es] > > > Dear Gaussian users, > I have one doubt. Which are the possible methods to calculate the Gibbs > energy using geometries optimized in gas phase? The calculation of > frequencies, + PCM, using these geometry is the most correct one? Or > taking the value for the free energy included in the PCM calculation is > also valid? And correcting the gas phase Gibbs energy by the free energy of the PCM calculation minus the energy also in PCM? > Hoping your comments, > Albert> > > > > > -- ----------------------------------------------------------------------------- Dr. habil. Andreas Klamt COSMOlogic GmbH&CoKG Burscheider Str. 515 51381 Leverkusen, Germany Tel.: +49-2171-73168-1 Fax: +49-2171-73168-9 e-mail: klamt+*+cosmologic.de web: www.cosmologic.de ----------------------------------------------------------------------------- COSMOlogic Your Competent Partner for Computational Chemistry and Fluid Thermodynamics -----------------------------------------------------------------------------