From owner-nwchem-users@emsl.pnl.gov Mon Mar 19 13:13:09 2007 Received: from odyssey.emsl.pnl.gov (localhost [127.0.0.1]) by odyssey.emsl.pnl.gov (8.13.8/8.13.8) with ESMTP id l2JKD8fe012668 for ; Mon, 19 Mar 2007 13:13:09 -0700 (PDT) Received: (from majordom@localhost) by odyssey.emsl.pnl.gov (8.13.8/8.13.8/Submit) id l2JKD8in012667 for nwchem-users-outgoing-0915; Mon, 19 Mar 2007 13:13:08 -0700 (PDT) X-Authentication-Warning: odyssey.emsl.pnl.gov: majordom set sender to owner-nwchem-users@emsl.pnl.gov using -f X-Ironport-SG: Throttle X-Ironport-SBRS: 1.6 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Ao8CAKuL/kWZEx0BdGdsb2JhbAA X-IronPort-AV: i="4.14,302,1170662400"; d="scan'208"; a="23971701:sNHT16554111" X-Authentication-Warning: chemik.chem.univ.gda.pl: maharan owned process doing -bs Date: Mon, 19 Mar 2007 21:12:30 +0100 (CET) From: Maciej Haranczyk To: nwchem-users@emsl.pnl.gov Subject: [NWCHEM] Constrain geoemtry optimization with PSPW Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-nwchem-users@emsl.pnl.gov Precedence: bulk Dear All, We encounter problems while performing constrain geoemtry optimization with NWChem. Our system is CH4 over metal surface (4 layers,16 atoms). Geometry is specified as Cartesian coordinates. We are using PSPW and periodic box is specified within pspw lattice block. 3 metal layers are kept frozen in geometry optimization via actlist. The would like to optimize CH4 over the surface with constraint that one of the C-H bond is set to 1.5 and kept fixed during the optimization. How can we do it ? We tried using zcoord. However, it doesnt work - the bond distance is changing during optimization. Aparently, it doesnt work because NWChem cannot convert input geometry into internal coordinates: AUTOZ failed to generate good internal coordinates. Cartesian coordinates will be used in optimizations. We tried to change crv_scaling paramter but still, NWChem cannot convert to internal coordinates. Is there any other way to perform constrin geometry optimization with keeping one bond distance fixed ? Thanks, Maciek -- Maciek Haranczyk maharan@chem.univ.gda.pl