From chemistry-request:~at~:ccl.net Fri Jun 17 17:28:16 2005 Received: from wproxy.gmail.com (wproxy.gmail.com [64.233.184.198]) by server.ccl.net (8.13.1/8.13.1) with ESMTP id j5HLSD3P027993 for ; Fri, 17 Jun 2005 17:28:13 -0400 Received: by wproxy.gmail.com with SMTP id 63so178930wri for ; Fri, 17 Jun 2005 14:28:12 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=TCJsDPHXN27Nq4P2wKfP1zgIHYMvaJhjZ9Q7CEWETJdBQoF1prYWZxRiTuPbD/3sbVpVrSxhIXdeFhT/Dd/q9TAmLqbisbakIZTQIEw07PHe/BxZq8MtjNedKeqqtWNgRkeLBd/+3y+wajKXjoaPY9TzB3g2dEWsIPAC7BlGtGw= Received: by 10.54.19.75 with SMTP id 75mr52655wrs; Fri, 17 Jun 2005 14:28:12 -0700 (PDT) Received: by 10.54.20.63 with HTTP; Fri, 17 Jun 2005 14:28:12 -0700 (PDT) Message-ID: <755a1e3b050617142875d94e96 = mail.gmail.com> Date: Fri, 17 Jun 2005 14:28:12 -0700 From: Pradyumna Shaakuntal Singh Reply-To: pradyu = u.arizona.edu To: chemistry = ccl.net Subject: Force Constants Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline X-Spam-Status: No, score=0.0 required=5.0 tests=RCVD_BY_IP autolearn=failed version=3.0.3 X-Spam-Checker-Version: SpamAssassin 3.0.3 (2005-04-27) on server.ccl.net Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by server.ccl.net id j5HLSG3P027997 Hi, I'm trying to compute the force constant for the superoxide ion (O2-) using MP2/6-31G*. using Gaussian 03. The value I get after running a frequency calculation is 11.03 mDyne/A. This converts to 68.9 eV/A^2. The experimental value (using spectroscopic constants) is about 37.8 eV/A^2. Clealy, I am quite off the mark. I suspect I am not interpreting the gaussian results correctly. Could anyone throw some light on whether I'm doign something wrong, and if so, what ? Any help is will be appreciated. Thanks, Pradyumna