From BRYAN.MARTEN@spcorp.com Fri Jul 24 08:39:41 1998 Received: from ans2.spri.sp.com (sp2.spcorp.com [198.16.9.3]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with SMTP id IAA25782 Fri, 24 Jul 1998 08:39:40 -0400 (EDT) Received: by sp2.spcorp.com id AA01300 (InterLock SMTP Gateway 3.0 for chemistry@www.ccl.net); Fri, 24 Jul 1998 08:39:34 -0400 Received: by sp2.spcorp.com (Internal Mail Agent-1); Fri, 24 Jul 1998 08:39:34 -0400 Mime-Version: 1.0 Date: Thu, 23 Jul 1998 15:09:24 -0400 Message-Id: <0017D086.1322@inet.spri.sp.com> From: BRYAN.MARTEN@spcorp.com (BRYAN MARTEN) Subject: PDB 3D queries? To: chemistry@www.ccl.net Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Description: cc:Mail note part Hi, What packages allow one to query the PDB in the same way one can query the Cambridge small-molecule database (eg. extract a histogram of NH...OC distances & angles, ring-ring distances & angles, atom-ring distances & angles, specified types of bond torsions and angles, etc.)? I will summarize responses. Thanks, Bryan Marten, PhD Schering-Plough Pharmaceuticals bryan.marten@spcorp.com From destack@unomaha.edu Fri Jul 24 09:30:16 1998 Received: from s-cwis.unomaha.edu (s-cwis.unomaha.edu [137.48.1.11]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with ESMTP id JAA26006 Fri, 24 Jul 1998 09:30:16 -0400 (EDT) Received: from cas.unomaha.edu (cas.unomaha.edu [137.48.34.40]) by s-cwis.unomaha.edu (8.8.5/8.8.5) with ESMTP id IAA09225 for ; Fri, 24 Jul 1998 08:25:54 -0500 (CDT) Received: from CAS/MAILQUEUE by cas.unomaha.edu (Mercury 1.21); 24 Jul 98 08:30:19 -600 Received: from MAILQUEUE by CAS (Mercury 1.21); 24 Jul 98 08:29:54 -600 Received: from zinc.unomaha.edu by cas.unomaha.edu (Mercury 1.21); 24 Jul 98 08:29:45 -600 Received: by zinc.unomaha.edu with Microsoft Mail id <01BDB6DD.C6753680@zinc.unomaha.edu>; Fri, 24 Jul 1998 08:33:46 -0500 Message-ID: <01BDB6DD.C6753680@zinc.unomaha.edu> From: "Douglas E. Stack" To: "'CCL'" Subject: Atomic Charges Date: Fri, 24 Jul 1998 08:33:09 -0500 Return-Receipt-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by www.ccl.net id JAA26006 Dear Cclers, In doing some B3LYP/6-31G* calculations on a medium size carbocation radical (ca. 330 basis sets), I find significant differences in the natural atomic charges when compared to Mulliken or electrostatic charges. A straightforward discussion of atomic charges is presented in "Practical Strategies for Electronic Calculations" by Hehre. This discussion describes two general methods; partitioning schemes, e.g. Muillken charges, and fitting schemes, e.g. electrostatic charges. I have the following questions: Are natural charges calculated by a partitioning scheme or a fitting scheme? Given that partitioning schemes don't converge with increasing basis set size, which method is best suited for B3LYP/6-31G* with 300+ basis sets? Are there any other good discussions (references) on how natural charges are generated? Do they converge with increasing basis set size? Which method is would one use in comparing charges of two carbon atoms, one with a hydrogen, one without? Another point of confusion about the charges obtained in this calculation, while the electrostatic charges show a low concentration at a certain carbon, a map of the electrostatic potential on to the total electron density shows a significant positive charge in the region around this same carbon. Since electrostatic charges are derived from a fitting scheme, shouldn't they mirror the map of the electrostatic potential on to the total electron density? I'll summarize this thread. Douglas E. Stack Assistant Professor Department of Chemistry University of Nebraska at Omaha Omaha, NE 68182-0109 (402) 554-3647 (402) 544-3888 (fax) destack@unomaha.edu From anh@chm.ulaval.ca Fri Jul 24 12:20:41 1998 Received: from cerberus.ulaval.ca (cerberus.ulaval.ca [132.203.250.10]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with ESMTP id MAA27381 Fri, 24 Jul 1998 12:20:40 -0400 (EDT) Received: from fluor.chm.ulaval.ca (fluor.chm.ulaval.ca [132.203.70.9]) by cerberus.ulaval.ca (8.8.7/8.7.3) with ESMTP id MAA24271; Fri, 24 Jul 1998 12:41:29 -0400 (EDT) Received: (from anh@localhost) by fluor.chm.ulaval.ca (8.6.12/8.6.12) id HAA19423; Fri, 24 Jul 1998 07:14:29 -0400 From: "Nguyen N. Anh" Message-Id: <9807240714.ZM19421@fluor.chm.ulaval.ca> Date: Fri, 24 Jul 1998 07:14:26 -0400 X-Mailer: Z-Mail (3.2.1 6apr95 MediaMail) To: chemistry@www.ccl.net Subject: Dipole moment with CASSCF Cc: help@gaussian.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Dear cclers, We are trying to calculate the dipole moments of various states of HCl+ by using CASSCF method available in Gaussian94. However, we suspect that these dipole moments are determined by using SCF (single-determinant) densities. Are we right? If yes, how to force Gaussian to calculate the dipole moments by using multi-determinental wavefuctions Thank you -- Nguyen Nam Anh Quebec, Canada E-mail: anh@chm.ulaval.ca WWW: http://promethium.chm.ulaval.ca/~anh/ From sjardino@iq.usp.br Fri Jul 24 15:33:31 1998 Received: from quim.iq.usp.br (quim.iq.usp.br [143.107.46.101]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with SMTP id PAA28551 Fri, 24 Jul 1998 15:33:23 -0400 (EDT) Received: (sjardino@localhost) by quim.iq.usp.br (8.6.10/SPARC10-IQ2.0) id QAA04218; Fri, 24 Jul 1998 16:24:06 -0300 Date: Fri, 24 Jul 1998 16:24:06 -0300 (EST) From: Sergio Augusto Jardino Filho To: chemistry@www.ccl.net Subject: CbsB1 keyword Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi everybody, In the last stage of the CBS-4 method there is the following keywords: #P Geom=AllCheck Guess=Read HF/CbsB1 SCF=Tight Could anyboby explain me the meaning of the keyword CbsB1? Thanks in advance. Sergio Jardino Universidade de Sao Paulo - Brazil