From chemistry-request@server.ccl.net Wed Apr 28 14:49:09 1999 Received: from www.ccl.net (www.ccl.net [192.148.249.5]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id OAA11419 for ; Wed, 28 Apr 1999 14:49:09 -0400 Received: from matrix.chem.jyu.fi (eloranta@matrix.chem.jyu.fi [130.234.8.17]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with ESMTP id OAA06477 Wed, 28 Apr 1999 14:45:59 -0400 (EDT) Received: (from eloranta@localhost) by matrix.chem.jyu.fi (8.8.7/8.8.7) id UAA27182 for chemistry@www.ccl.net; Wed, 28 Apr 1999 20:49:36 +0300 From: Jussi Eloranta Message-Id: <199904281749.UAA27182@matrix.chem.jyu.fi> Subject: UHF convergence To: chemistry@www.ccl.net Date: Wed, 28 Apr 1999 20:49:35 +0300 (EEST) Content-Type: text Dear netters, What is the best way to obtain proper UHF convergence of, for example, hydrogen molecule with gaussian 98? If I calculate the ground state PES for it with UHF then I keep getting convergence exclusively to the singlet wavefunction. The S**2 is zero all the time and the dissociation limit corresponds to the (incorrect) case of RHF. However, some testing with stable=opt keyword resulted in correct result: The dissociation limit is correct and value changes >from 0 (near equil. distance) to 1 at large distances. The drawback of this is approach that for large basis sets and heavier atoms this procedure appears to be extremely slow. Any ideas how to get the correct UHF convergence faster with g98? Best regards, Jussi Eloranta University of Jyvaskyla Finland From chemistry-request@server.ccl.net Wed Apr 28 08:21:43 1999 Received: from unlp.unlp.edu.ar (unlp.unlp.edu.ar [163.10.0.67]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id IAA06794 for ; Wed, 28 Apr 1999 08:21:38 -0400 Received: from nahuel.biol.unlp.edu.ar (nahuel.biol.unlp.edu.ar [163.10.7.1]) by unlp.unlp.edu.ar (8.9.1a/8.9.1) with SMTP id MAA20865 for ; Wed, 28 Apr 1999 12:24:24 GMT Received: from jubert2.biol.unlp.edu.ar by nahuel.biol.unlp.edu.ar (SMI-8.6/SMI-SVR4) id JAA21419; Wed, 28 Apr 1999 09:17:09 -0400 Message-Id: <3.0.1.32.19990428091800.0068d508@nahuel.biol.unlp.edu.ar> X-Sender: pis_diez@nahuel.biol.unlp.edu.ar X-Mailer: Windows Eudora Light Version 3.0.1 (32) Date: Wed, 28 Apr 1999 09:18:00 -0300 To: chemistry@ccl.net From: "Dr. Reinaldo Pis Diez" Subject: Stable+freq calculations in g94/8 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Dear CCL'ers, I'm doing some calculations (geometry optimizations) on small systems using DFT as implemented in Gaussian 94 and 98. Once the geometry is optimized, I do a stable(opt) job on the wave function corresponding to that geometry. I find very often that the wf is unstable, but the opt option in the stable keyword works well and overcome the unstability problem. Then, I try a frequency calculation using guess(read) and geom(check) but the calculation is performed on the unstable wf instead of the stable one!! How can I perform the frequency job using the stable wf? Which combination of keywords am I missing? Thanks in advance. Regards, Reinaldo pis_diez@biol.unlp.edu.ar From chemistry-request@server.ccl.net Wed Apr 28 08:51:35 1999 Received: from swan2.uspnet.usp.br (swan2.uspnet.usp.br [143.107.253.69]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id IAA07111 for ; Wed, 28 Apr 1999 08:51:24 -0400 Received: from ligquim ([143.107.194.89]) by swan2.uspnet.usp.br (8.9.1a/8.9.1) with SMTP id JAA26623 for ; Wed, 28 Apr 1999 09:44:47 -0300 (EST) Message-ID: <001201be9175$5545ee00$0100005a@ligquim.ffclrp.usp.br> From: "Sergio Emanuel Galembeck" To: "CCL mail list" Subject: G98: ZPE in semiempirical calcs Date: Wed, 28 Apr 1999 09:47:48 -0300 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.5 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Content-Transfer-Encoding: 8bit Dear Netters, I am making semiempirical calculations using G98, and I have a question: Is correct to sum the zero-point energy in the electronic energy? Thank you very much, Sérgio ============================================== Sergio Emanuel Galembeck Assistant Professor in Physical Chemistry Laboratorio de Modelagem Molecular Departamento de Quimica Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto Universidade de Sao Paulo fax: +55-16-633-81-51 e-mail: segalemb@usp.br =============================================== From chemistry-request@server.ccl.net Wed Apr 28 12:38:21 1999 Received: from www.ccl.net (www.ccl.net [192.148.249.5]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id MAA09800 for ; Wed, 28 Apr 1999 12:38:21 -0400 Received: from nano.chem.nwu.edu (nano.chem.nwu.edu [129.105.14.190]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with SMTP id MAA06098 Wed, 28 Apr 1999 12:35:11 -0400 (EDT) Received: from nano.chem.nwu.edu ([129.105.14.190]) by nano.chem.nwu.edu (WESMTP 2.1 [Sep 22 1998]) with SMTP id 604980625; Wed, 28 Apr 1999 16:41:12 GMT Date: Wed, 28 Apr 1999 11:41:10 -0500 From: "G. Rechtsteiner" Subject: Free Energy To: CHEMISTRY@www.ccl.net Message-Id: <4.1.19990428113525.00a18be0@nano.chem.nwu.edu> X-Sender: greg@nano.chem.nwu.edu X-Mailer: QUALCOMM Windows Eudora Pro Version 4.1 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Hello: I have recently doen some calculations using Gaussian 98W and I have come across the following question: What value reported from the Thermochemical Analysis is the correct value to use for the Free Energy of the molecule. In Exploring Chemistry with Electronic Structure Methods, they give the following labels: Zero-point correction= (Hartree/Particle) Thermal correction to Energy= Thermal correction to Enthalpy= Thermal correction to Gibbs Free Energy= Eo Sum of electronic and zero-point Energies= E Sum of electronic and thermal Energies= H=E+RT Sum of electronic and thermal Enthalpies= G=H-TS Sum of electronic and thermal Free Energies= So, my question is, if I want to compare the Free Energies of a set of molecules, do I compare the last value shown (which includes the Electronic Energies) or do I subtract out the Electronic Energies? Which is the standard method used, of if it is something different, what is it? Thank you, Greg Rechtsteiner Northwestern University Department of Chemistry 2145 Sheridan Rd. Evanston, IL 60208 From chemistry-request@server.ccl.net Fri Apr 23 06:19:12 1999 Received: from rs5.thch.unipg.it (rs5.thch.unipg.it [141.250.9.2]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id GAA32560 for ; Fri, 23 Apr 1999 06:19:10 -0400 Received: (from nunzi@localhost) by rs5.thch.unipg.it (AIX4.2/UCB 8.7/8.7) id MAA34812 for chemistry@server.ccl.net.; Fri, 23 Apr 1999 12:15:15 +0200 (MDT) Date: Fri, 23 Apr 1999 12:15:15 +0200 (MDT) From: Francesca Nunzi Message-Id: <199904231015.MAA34812@rs5.thch.unipg.it> To: -v@rs5.thch.unipg.it, chemistry@server.ccl.net Subject: POAV Analysis by Haddon Hello everybody, I'm looking for the QCMP044 program for the calculation of pyramidalization angle in nonplanar conjugated organic molecules. R.C Haddon was interested in POAV Analysis. Have you ever heard something about this? Thank you, Francesca