From chemistry-request@server.ccl.net Sun Mar 24 02:22:22 2002 Received: from 263.net ([202.96.44.43]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g2O7Lnp21480 for ; Sun, 24 Mar 2002 02:22:21 -0500 Received: by 263.net (Postfix, from userid 60001) id 817D11C6DCB53; Sun, 24 Mar 2002 15:18:28 +0800 (CST) Subject: Fw:(by songyunlong@263.net)=?gb2312?B?SG93IHRoZSBwYXJ0aWFsIGNoYXJnZXMgYmUgY29tcHV0ZWQgaW4gQ1ZGRiBmb3JjZSBmaWVs MIME-Version: 1.0 Message-ID: <3C994EBB.00000D.11281@mta4> Date: Thu, 21 Mar 2002 11:08:43 +0800 (CST) From: "宋云龙" To: chemistry@ccl.net Subject: =?gb2312?B?SG93IHRoZSBwYXJ0aWFsIGNoYXJnZXMgYmUgY29tcHV0ZWQgaW4gQ1ZGRiBmb3JjZSBmaWVs ZA==?= X-Priority: 3 X-Originating-IP: [61.171.34.6] X-Mailer: Coremail2.0 Copyright Tebie Ltd., 2001 Dear all the CCLers: I am a user of InsightII of Accelrys(former MSI). When I perform comutations,such as molecular minization or dynamics,I often use CVFF force field. I always use FF (Force Field). This command is activated on the left side by clicking on the FF button. Then select Forcefield/Potentials and make sure that all of the settings as follows. Potential Action [Fix] Partial Charge Action [Fix] Formal Charge Action [Fix or Accept] My question is how the partial charges of my molecules are computed? In my opinion,the partial charges are part of the CVFF force field. When CVFF is used, the partial charges are automatically loaded from the system file. This is quite different from MM2 (Tripos) method which often calculate partial charge through Gasteiger-Huckel method for small molecules.Is this so? I have referred several papers, but find no how the charges are computed. I am eager to get any helpful suggestions. Thank you in advance! Song Yunlong songyunlong@263.net __________________________________________ 邮件到了吗?手机告诉你(http://mail.263.net/mmail/index.html) 点击下载95963上网直通车(http://www.263.net/0ji/StarDialer.exe) 我拿什么来诱惑你(http://95963.263.net/) 化妆品三折,香水半价(http://shopping.263.net/class004.htm) From chemistry-request@server.ccl.net Sun Mar 24 13:30:07 2002 Received: from uni-freiburg.de ([132.230.2.65]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g2OIU6p04311 for ; Sun, 24 Mar 2002 13:30:07 -0500 Received: from [132.230.171.109] (account oliver.hucke@physchem.uni-freiburg.de HELO physchem.uni-freiburg.de) by uni-freiburg.de (CommuniGate Pro SMTP 3.4.7) with ESMTP-TLS id 5750555; Sun, 24 Mar 2002 19:29:58 +0100 Message-ID: <3C9E1C79.B5A44F67@physchem.uni-freiburg.de> Date: Sun, 24 Mar 2002 19:35:37 +0100 From: Oliver Hucke X-Mailer: Mozilla 4.79 [en] (WinNT; U) X-Accept-Language: en MIME-Version: 1.0 To: chemistry@ccl.net, songyunlong@263.net Subject: Re: How the partial charges be computed in CVFF force field References: <3C994EBB.00000D.11281@mta4> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Dear Song Yunlong, I have used InsightII in conjunction with the charmm forcefield and Delphi to perform electrostatics calculations. In this case the partial charges are obtained from the topology file of the forcefield. It should be the same with cvff? In the directory [Insight instalation path]/I2000/irix6m4/biosym_lib/ I can find a file cvff.rlb which seems to contain the atomic partial charges... Best, Oliver > Dear all the CCLers: > I am a user of InsightII of Accelrys(former MSI). When I perform comutations,such as molecular minization or dynamics,I often use CVFF force field. I always use FF (Force Field). This command is activated on the left side by clicking on the FF button. Then select Forcefield/Potentials and make sure that all of the settings as follows. > Potential Action [Fix] > > Partial Charge Action [Fix] > > Formal Charge Action [Fix or Accept] > > My question is how the partial charges of my molecules are computed? In my opinion,the partial charges are part of the CVFF force field. When CVFF is used, the partial charges are automatically loaded from the system file. This is quite different from MM2 (Tripos) method which often calculate partial charge through Gasteiger-Huckel method for small molecules.Is this so? I have referred several papers, but find no how the charges are computed. > > I am eager to get any helpful suggestions. > > Thank you in advance! > > Song Yunlong > songyunlong@263.net > -- ____________________________________________________________________________ Oliver Hucke Inst. fuer Physikalische Chemie II Universitaet Freiburg Albertstr. 23a D-79104 Freiburg Tel. : +49-761-203-5130 (/-6179) Fax. : +49-761-203-6189 email: Oliver.Hucke@physchem.uni-freiburg.de ____________________________________________________________________________ From chemistry-request@server.ccl.net Sun Mar 24 20:50:13 2002 Received: from sungod.ccs.yorku.ca ([130.63.236.104]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g2P1oDp13957 for ; Sun, 24 Mar 2002 20:50:13 -0500 Received: from sunburn.ccs.yorku.ca (sunburn.ccs.yorku.ca [130.63.236.110]) by sungod.ccs.yorku.ca (8.9.3/8.9.3) with ESMTP id UAA25224; Sun, 24 Mar 2002 20:50:00 -0500 (EST) Received: from localhost (serge@localhost) by sunburn.ccs.yorku.ca (8.9.3/8.9.3) with ESMTP id UAA06001; Sun, 24 Mar 2002 20:49:53 -0500 (EST) X-Authentication-Warning: sunburn.ccs.yorku.ca: serge owned process doing -bs Date: Sun, 24 Mar 2002 20:49:50 -0500 (EST) From: "S.I. Gorelsky" X-X-Sender: serge@sunburn.ccs.yorku.ca To: Hongbin Du cc: CHEMISTRY@ccl.net Subject: Re: CCL:Mulliken population analysis In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII > Dear CCLers, > It seems to me that Gaussian program does not provide a complete Mulliken > population analysis which gives the composition of the MOs in terms of > various AOs. Could someone please recommand any program that can? Thanks in > advance. > > Hongbin Du, PhD > Steacie Institute for Molecular Sciences > National Research Council > Ottawa, Ontario K1A 0R6, Canada Here is the program (AOMix) which does what you ask: http://www.obbligato.com/SOFTWARE/SG/AOMix/ With regards, Serge ________________________________________________________________ S. I. Gorelsky, Ph.D. Department of Chemistry, York University 4700 Keele Street, Toronto, Ontario M3J 1P3 Canada Phone: 416-736-2100 ext#70131 Fax: 416-736-5936 http://www.chem.yorku.ca/grad/SG/ ________________________________________________________________