From owner-nwchem-users@emsl.pnl.gov Wed Sep 1 05:05:26 2004 Received: from odyssey.emsl.pnl.gov (localhost [127.0.0.1]) by odyssey.emsl.pnl.gov (8.12.10/8.12.10) with ESMTP id i81C5QcF020795 for ; Wed, 1 Sep 2004 05:05:26 -0700 (PDT) Received: (from majordom@localhost) by odyssey.emsl.pnl.gov (8.12.10/8.12.10/Submit) id i81C5QTV020793 for nwchem-users-outgoing; Wed, 1 Sep 2004 05:05:26 -0700 (PDT) Date: Wed, 01 Sep 2004 08:05:14 -0400 From: "Harrison, Robert J." Subject: RE: NWChem MP2 results different from Gaussian03 MP2? To: Paul Ha-Yeon Cheong , nwchem-users@emsl.pnl.gov Message-id: MIME-version: 1.0 X-MIMEOLE: Produced By Microsoft Exchange V6.5.7226.0 Content-type: text/plain; charset=iso-8859-1 Thread-Topic: NWChem MP2 results different from Gaussian03 MP2? thread-index: AcSPzysx+h5/hNCXRr6X0VUIut8pyAATAX0q Content-class: urn:content-classes:message X-MS-Has-Attach: X-MS-TNEF-Correlator: Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by odyssey.emsl.pnl.gov id i81C5PcF020788 Sender: owner-nwchem-users@emsl.pnl.gov Precedence: bulk Do the SCF energies agree? There can be multiple UHF solutions. Are you using the same frozen core options? In NWChem, the default is correlate all orbitals. Robert -----Original Message----- From: owner-nwchem-developers@emsl.pnl.gov on behalf of Paul Ha-Yeon Cheong Sent: Tue 8/31/2004 10:49 PM To: nwchem-users@emsl.pnl.gov Cc: Paul Ha-Yeon Cheong Subject: NWChem MP2 results different from Gaussian03 MP2? Dear NWChem community, I ran MP2 single points jobs at the same basis set with NWChem and Gaussian03. However, the MP2 energies are quite different even though the geometries are exactly the same (copy, paste, verified). Is there a reason why the energies are different? Does NWChem do something different in calculating the SCF and/or MP2 compared to Gaussian? How can I run the NWChem calculations to get consistent results with Gaussian? I attach parts of the input files and the respective output energies below. Sincerely yours, Paul Ha-Yeon Cheong -------- NWChem INPUT: -------- basis spherical * library 6-31G* end scf thresh 1.0e-8 end task mp2 ====== Result of NWChem MP2 calculation: ====== "Total SCF energy = -974.008605304341" "Total MP2 energy -977.059895142115" MP2 correction = 3.05128983777" -------- Gaussian03 INPUT: -------- #mp2/6-31g(d) guess=read geom=check ====== Result of Gaussian03 MP2 calculation: ====== "E2 = -0.3029098694D+01 EUMP2 = -0.97704154287316D+03" _______________________________________ Paul Ha-Yeon Cheong Member of the K. N. Houk Group Department of Chemistry and Biochemistry University of California, Los Angeles 607 Charles E. Young Drive, East Los Angeles, CA 90095