From owner-nwchem-users@emsl.pnl.gov Mon Jan 7 11:24:26 2008 Received: from odyssey.emsl.pnl.gov (localhost [127.0.0.1]) by odyssey.emsl.pnl.gov (8.14.1/8.14.1) with ESMTP id m07JOPvL006784 for ; Mon, 7 Jan 2008 11:24:26 -0800 (PST) Received: (from majordom@localhost) by odyssey.emsl.pnl.gov (8.14.1/8.14.1/Submit) id m07JOPgU006783 for nwchem-users-outgoing-0915; Mon, 7 Jan 2008 11:24:25 -0800 (PST) X-Authentication-Warning: odyssey.emsl.pnl.gov: majordom set sender to owner-nwchem-users@emsl.pnl.gov using -f X-Ironport-SG: No_SBRS X-Ironport-SBRS: None X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ao8CAK0KgkeGSiZk/2dsb2JhbACoPQ X-IronPort-AV: E=Sophos;i="4.24,254,1196668800"; d="scan'208";a="62674325" From: "Michael E. Green" Subject: [NWCHEM] more on Gaussian/NWChem discrepancy, and spherical coords To: nwchem-users@emsl.pnl.gov X-Mailer: CommuniGate Pro Web Mailer v.4.0.5 Date: Mon, 07 Jan 2008 14:24:17 -0500 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format="flowed" Content-Transfer-Encoding: 8bit Sender: owner-nwchem-users@emsl.pnl.gov Precedence: bulk Hello all, Based on a recent thread, the discrepancy between Gaussian and NWChem is largely due to the difference between spherical and Cartesian coordinates. As I understood the conclusion, one should use spherical for more accurate results, as these were the coords used in developing the basis sets. (Did I understand this correctly?) We do observe that the discrepancy with Gaussian drops by an order of magnitude with spherical coords. We now have another problem, assuming that spherical coords are better. Is there any way to impose a constraint on a distance between two atoms with spherical coords in NWChem? Thanks for any help. Mike Green ********************** Michael E. Green Professor of Chemistry City College of New York 160 Convent Avenue New York NY 10031 (212)650-6034 (212)650-6107 (fax) green@sci.ccny.cuny.edu