From chemistry-request@ccl.net Fri Jul 8 05:13:23 2005 Received: from distrib2.mail.u-psud.fr (distrib2.mail.u-psud.fr [129.175.34.154]) by server.ccl.net (8.13.1/8.13.1) with ESMTP id j689DJml019379 for ; Fri, 8 Jul 2005 05:13:20 -0400 Received: from intfiltre3.mail.u-psud.fr (intfiltre3.mail.u-psud.fr [129.175.34.151]) by distrib2.mail.u-psud.fr (8.12.10/8.12.0.Beta10) with ESMTP id j689DE04018574 for ; Fri, 8 Jul 2005 11:13:14 +0200 Received: from post1.mail.u-psud.fr (post1.mail.u-psud.fr [129.175.34.87]) by intfiltre3.mail.u-psud.fr (8.12.10/8.12.0.Beta10) with ESMTP id j689Ct80005378 for ; Fri, 8 Jul 2005 11:13:13 +0200 Received: from ext.lcp.u-psud.fr (ext.lcp.u-psud.fr [129.175.100.5]) by post1.mail.u-psud.fr (8.12.10/8.12.0.Beta10) with ESMTP id j689B6u3027585 for ; Fri, 8 Jul 2005 11:11:07 +0200 Received: from lcp.u-psud.fr (pc7.lcp.u-psud.fr [129.175.101.37]) by ext.lcp.u-psud.fr (8.13.1/8.13.1) with ESMTP id j689B9FE011409 for ; Fri, 8 Jul 2005 11:11:10 +0200 Message-ID: <42CE432D.2010104 !! lcp.u-psud.fr> Date: Fri, 08 Jul 2005 11:11:09 +0200 From: Pierre Archirel User-Agent: Mozilla/5.0 (X11; U; Linux i686; fr; rv:1.4.1) Gecko/20031114 X-Accept-Language: fr, en MIME-Version: 1.0 To: chemistry !! ccl.net Subject: CCL: dissociation problem Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Scanned: by amavis X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=failed version=3.0.4 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on server.ccl.net Dear Elmar, I would say the issue you are refering to has nothing to do with PCM, but is probably due to a DFT artifact, which is the wrong dissociation of NaCl, even in the gas phase. Your asymptotic system is a singlet open shell, with two electrons, alone in their orbitals. DFT poorly addresses this situation, because of the approximative cancelation of the self interaction. To check this: 1- verify that at the crude HF level, your long range PCM energy is the sum of the PCM energies of the fragments. 2- check if your (gas phase) long range B3LYP calculation yields fragments with 0 charges. If not, DFT is of no help to you. P. __________________________________________________________ Pierre Archirel Groupe de Chimie Thiorique Laboratoire de Chimie Physique Tel: 01 69 15 63 86 Bat 349 Fax: 01 69 15 61 88 91405 Orsay Cedex France pierre.archirel !! lcp.u-psud.fr __________________________________________________________