From owner-nwchem-users@emsl.pnl.gov Thu Dec 14 08:41:35 2006 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 kBEGfYdp029071 for ; Thu, 14 Dec 2006 08:41:35 -0800 (PST) Received: (from majordom@localhost) by odyssey.emsl.pnl.gov (8.13.8/8.13.8/Submit) id kBEGfYSs029070 for nwchem-users-outgoing-0915; Thu, 14 Dec 2006 08:41:34 -0800 (PST) X-Authentication-Warning: odyssey.emsl.pnl.gov: majordom set sender to owner-nwchem-users@emsl.pnl.gov using -f X-Ironport-SG: OK_Domains X-Ironport-SBRS: 1.6 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgAAAOMNgUWGSiZkdGdsb2JhbACNXAE X-IronPort-AV: i="4.12,170,1165219200"; d="scan'208"; a="10028954:sNHT17358586" From: "Vasiliy S. Znamenskiy" Subject: Re: [NWCHEM] Point Charges To: "Deskins, Nathaniel A" , X-Mailer: CommuniGate Pro Web Mailer v.4.0.5 Date: Thu, 14 Dec 2006 11:41:27 -0500 Message-ID: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="windows-1251"; format="flowed" Content-Transfer-Encoding: 8bit Sender: owner-nwchem-users@emsl.pnl.gov Precedence: bulk B.2.2 Job 2. Compute the energy with applied field An external field may be simulated with point charges. The charges here apply a field of magnitude 0.01 atomic units to the atom at the origin. Since the basis functions have not been reordered by the additional centers we can also restart from the previous vectors, which is the default for a restart job. restart ne title "Neon in electric field" geometry units atomic bq1 0 0 100 charge 50 ne 0 0 0 bq2 0 0 -100 charge -50 end task scf The final energy should be -128.496441, which together with the previous field-free result yields an estimate for the polarizability of 1.83 atomic units. Note that by default NWChem does not include the interaction between the two point charges in the total energy (section 6). On Thu, 14 Dec 2006 08:15:59 -0800 "Deskins, Nathaniel A" wrote: >Hello NWChem Users, > Is there a simple way to include point charges with a >hf/dft >calculation? I looked in the manual and the closest thing >I could find >was the QM/MM section, which seems rather complicated and >overboard for >adding point charges. > >Thank you. >Aaron Vasiliy S. Znamenskiy Cell Phone: 1(917)532-4377 Work Phone: 1(212)650-6034 Fax: 1(212)650-6107 Marshak Science Building J-1130 Convent Avenue & 138th Stret New York, New York 10031 http://web.sci.ccny.cuny.edu/~znamensk