From chemistry-request |-at-| server.ccl.net Fri Mar 1 16:42:30 2002 Received: from mserver.wlu.ca ([192.54.242.16]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g21LgU525930 for ; Fri, 1 Mar 2002 16:42:30 -0500 Received: from dgoussev ([192.219.240.167]) by mserver.wlu.ca (8.10.1/8.10.1) with SMTP id g21Lfvf26967 for ; Fri, 1 Mar 2002 16:41:57 -0500 (EST) Message-ID: <007801c1c172$53e120e0$a7f0dbc0-: at :-wlu.ca> From: "Dmitri Goussev \(Gusev\)" To: Subject: zero-point energy correction Date: Fri, 1 Mar 2002 16:42:11 -0600 MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Dear Friends: It is my understanding that electronic energies from good (or high) quality QM calculations are usually modified by addition of zero-point energies, for example, to compare two isomers. I believe that zero-point energies are normally obtained from relatively low-quality (for both theory and basis) frequency calculations. This makes sense only if zero-point energies (unlike the electronic ones) are not critically influenced by the quality of the calculation. Is this true? Thanks! Dmitri Goussev (Gusev), Associate Professor Chemistry Department Wilfrid Laurier University Waterloo, Ontario Canada N2L 3C5 Voice: (519) 884-1970, ext. 2736 Fax: (519) 746-0677 E-mail: dgoussev-: at :-wlu.ca