From owner-chemistry@ccl.net Wed Mar 27 03:19:00 1996 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.7.1/950822.1) id DAA29637; Wed, 27 Mar 1996 03:04:23 -0500 (EST) Received: from shiva.jussieu.fr for hebant@ext.jussieu.fr by bedrock.ccl.net (8.7.1/950822.1) id DAA10876; Wed, 27 Mar 1996 03:04:22 -0500 (EST) Received: from idf.ext.jussieu.fr (idf.ext.jussieu.fr [134.157.81.129]) by shiva.jussieu.fr (8.7.3/jtpda-5.2) with ESMTP id JAA14974 ; Wed, 27 Mar 1996 09:04:16 +0100 (MET) Received: from [134.157.11.16] by idf.ext.jussieu.fr (8.6.10/jtpda-4.0) with SMTP; Wed, 27 Mar 1996 09:04:12 +0100 X-Sender: hebant@idf.ext.jussieu.fr Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 27 Mar 1996 09:03:41 +0100 To: Carlos.Andre@bbs.centroin.com.br (Carlos Andre) From: hebant@ext.jussieu.fr (Pascal HEBANT) Subject: Re: CCL:chemistry-request@ccl.net Cc: chemistry@ccl.net Voce tem que visitar o endereco WWW seguinte : http://www.ccl.net/chemistry.html Precisa tambem de falar ingles, o brasiliero nao e uma lingua que todo o mundo entende... Pascal ***************************************************************************** Pascal HEBANT Laboratoire d'Electrochimie et de Chimie Analytique Ecole Nationale Superieure de Chimie de Paris 11 rue Pierre et Marie Curie 75005 Paris FRANCE tel: 33 (1) 44 27 66 94 fax: 33 (1) 44 27 67 50 http://alcyone.enscp.jussieu.fr/Pages/LECA/Electrochimie.html ***************************************************************************** From mas@qc.ag-berlin.mpg.de Wed Mar 27 06:19:05 1996 Received: from enterprise.qc.ag-berlin.mpg.de for mas@qc.ag-berlin.mpg.de by www.ccl.net (8.7.1/950822.1) id FAA01326; Wed, 27 Mar 1996 05:41:09 -0500 (EST) Received: by enterprise.qc.ag-berlin.mpg.de (AIX 3.2/UCB 5.64/4.03) id AA14759; Wed, 27 Mar 1996 11:41:08 +0100 From: mas@qc.ag-berlin.mpg.de (Marek Sierka) Message-Id: <9603271041.AA14759@enterprise.qc.ag-berlin.mpg.de> Subject: Help: Semiempirical Periodic Calculations To: chemistry@www.ccl.net Date: Wed, 27 Mar 1996 11:41:06 +0100 (NFT) X-Mailer: ELM [version 2.4 PL23] Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Dear netters, I am looking for a program that can perform semiempirical calculations (MNDO, AM1) on peridic crystal structures. I've heard about one, namely MOSOL, written by J.P Stewart, but I'm wondering how does it work and I would like to know its capabilities before I consider to order it from QCPI. If anybody used it, please e-mail me. I will send the summary to the net. Thanks in advance, -- Marek Sierka e-mail: mas@gea.qc.ag-berlin.mpg.de From Patrick.Bultinck@rug.ac.be Wed Mar 27 07:19:04 1996 Received: from mserv.rug.ac.be for Patrick.Bultinck@rug.ac.be by www.ccl.net (8.7.1/950822.1) id HAA02343; Wed, 27 Mar 1996 07:18:52 -0500 (EST) Received: from allserv.rug.ac.be by mserv.rug.ac.be with SMTP id AA27521 (5.67b/IDA-1.5 for ); Wed, 27 Mar 1996 13:18:48 +0100 Received: from hartree1.rug.ac.be by allserv.rug.ac.be (5.x/SMI-SVR4) id AA13556; Wed, 27 Mar 1996 13:18:42 +0100 Date: Wed, 27 Mar 1996 13:15:24 +0100 (NFT) From: Patrick Bultinck To: CCL Subject: 2:electrostatics and dipole moment Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear, There seems to be some mis-understanding. I know that the VALUE for the dipole moment is indeed origin-independant for a neutral species, and not so for a charged species. What I mean is : 'How to chose an origin for a neutral species IF you need not only the value ?'. I will give an example : Say C3v NH3 and C2v H2O. a) Complexes of the first with e.g. Na+ gives a larger interaction energy than with H2O. b) mu H2O > mu NH3 In an article (I will not give the reference, since I would not like to let it look like I think something negative on some author, which no doubt knows more about this than I do) I found an explanation which should go as follows : We know that mu H2O > mu NH3, so also that Z*mu is larger for the H2O complex than for the NH3 complex. On the other hand, the interaction also depends on r, the distance between the dipole moment and the point charge or ion. The author found that the dipole vector in NH3 lies more to the right than in H2O (see figure). H H \ \ H-N O / / H H *-> *-> (PURELY QUALITATIVE AND EXAGERATED, please...) For the interaction with an ion, r(NH3) would be substantially smaller than in case of H2O, which SHOULD explain the observed electrostatic interaction differences. BUT, I did some calculations myself, and the trouble is that I have great suspicions that the origin was simply put in the center of mass, which seems to me as an unjustifiable approach...I would put the origin where other multipoles are minimal. It seems to me that you could even play a little with the results, say you let all the chemical properties the same, but play a little with isotopes, and get another result, which should influence you perception of the metal-ligand bond. So the question was : 'If I really need to have a method not only to have the value of the dipole moment, but also it's spacial position (origin, we have all components from our wavefunction, aka the value of the x-xomponent, y etc.), how should I do this'. Thanks, ******************************************************************************* Patrick Bultinck Macrocycles Quantum Chemical Ph. D. Student Calculations Dept. Inorganic & Physical Chemistry University of Ghent Tel. Int'l code/32/9/264.44.44 Krijgslaan 281 (S-3) Fax. Int'l code/32/9/264.49.83 9000 Gent E-mail : Patrick.Bultinck@rug.ac.be Belgium http://allserv.rug.ac.be/~pbultink/ ******************************************************************************* From owner-chemistry@ccl.net Wed Mar 27 09:19:04 1996 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.7.1/950822.1) id IAA04486; Wed, 27 Mar 1996 08:48:38 -0500 (EST) Received: from smaug.physics.mun.ca for uli@smaug.physics.mun.ca by bedrock.ccl.net (8.7.1/950822.1) id IAA12786; Wed, 27 Mar 1996 08:48:35 -0500 (EST) Received: by smaug.physics.mun.ca (940816.SGI.8.6.9/911001.SGI) id KAA08416; Wed, 27 Mar 1996 10:19:19 -0330 Date: Wed, 27 Mar 1996 10:19:19 -0330 (NST) From: Uli Salzner To: ccl Subject: meaning of eigenvalues in dft Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII recently I posted a question concerning the meaning of eigenvalues in density functional theory. I received many very helpful references. Thanks to everybody who took the time to answer. Here is the original question and a summary of the answers: Callaway and March (Sol. State Phys. 38, 135 (1984)) discuss the meaning or better "non-meaning" of eigenvalues in density functional methods. It seems that the band gap of a sufficiently large system can be calculated by taking the energy difference between the valence and the conduction band but that the difference between HOMO and LUMO in molecules can not be used in connection with Koopman's theorem. I am wondering whether this is the end of the story or whether it is possible for practical purposes to use HOMO and LUMO levels. Would that be a crude approximation or total garbage? I am especially interested in density functional methods as implemnented in GAUSSIAN 94, which lists the HOMO and LUMO levels in DFT just as for HF. It is quite tempting to use them and as far as I tried the results seem to be reasonable. What I would like to do is to compare solid state calculations (with Cerius2) and calculations for oligomers of increasing size and try to extrapolate towards the solid. I am only interested in systems at 0 temperature where the occupation of the one-electron functions is either 0 or 1. I would be very thankful for any comments or related references. A summary of the answers will be posted. ***************************************************************************** Dear Uli Salzner, a good functional would give perfect ionization potential (IP). See Baerends et al. I.J.Q.C. 52 (1994) 711 and Krieger et al. DFT ed. E.K.U. Gross and R.M. Dreizler (1995) p 191, Plenum Press N.Y. The bad IP shows the deficiencies of the funtionals. I've read a paper in which the authors shifted simply the eigenvalues (e.g. subtracted 3 eV from the upper eigenvalues), and got good agreement with the experiment (UPS). (?!) I think some progress is expected in this field in the near future (may be on the ICTCP II). -- Gabor I. Csonka e-mail: csonka@incm.u-nancy.fr Lab.Chimie Theorique Universite Henri Poincare B.P. 239 54506 Vandoeuvre-les-Nancy FRANCE tel: +33-83.91.25.29 fax: +33-83.91.25.30 ****************************************************************************** i think that the work of Levy, and others actually shows that for the EXACT density, and exchange-correlation functional the KS orbital-energies will be -IP..... but of course any approximation to these may not have any meaning. Dr. Noj Malcolm Noj.Malcolm@man.ac.uk ****************************************************************************** > Callaway and March (Sol. State Phys. 38, 135 (1984)) discuss the meaning > or better "non-meaning" of eigenvalues in density functional methods. It > seems that the band gap of a sufficiently large system can be calculated > by taking the energy difference between the valence and the conduction > band but that the difference between HOMO and LUMO in molecules can not > be used in connection with Koopman's theorem. I am wondering whether this > is the end of the story or whether it is possible for practical purposes > to use HOMO and LUMO levels. Would that be a crude approximation or total > garbage? The question of how to compute excitation energies with DFT is not solved, but useful discussions can be found, by people like Kohn, Theophilou (difficult to read), Gross and Nagy. The idea of the Slater transition state is important in this discussion. A recent paper dealing with the subject is Mel Levy, Excitation energies from density-functional orbital energies, Physical Review A, Vol. 52, No. 6 (December 1995), pp. R4313-R4315. The classical paper is E. K. U. Gross, L. N. Oliveira and W. Kohn, Phys. Rev. A 37, 2805 (1988), and two other papers in the same journal (following this one). Also have a look at Agnes Nagy, Exact ensemble exchange potentials for multiplets, International Journal of Quantum Chemistry, Suppl. 29 (1995), pp. 297-301. Hope this helps... Best regards, Alain -- Alain Kessi (alain.kessi@psi.ch) at Paul Scherrer Institut, Zuerich, Switzerland ***************************************************************************** Kohn-Sham eigenvalues do have meaning, but not the same as in HF. Moreover the full meaning of KS eigenvalue is not yet clear, but new discoveries are made. In particular, there is numerical evidence that certain differences of eigenvalues (orbital energies) are related to the average of true singlet/triplet excitation energies in atoms, provided that the exact V_xc potential is used (work of A. Savin and co-workers presented at the 1996 APS meeting). Here are some references about the meaning(s) of Kohn-Sham eigenvalues: 1. Density Functional Theory of Atoms and Molecules, by Parr and Yang, section 7-6 (Oxford Press, 1990) : an overview. 2. Slater, "The SCF field for Molecules and Solids: Quantum Theory of Molecules and Solids", vol. 4, New York (McGraw Hill, 1974); based on semi-empirical X-alpha and thus a little out of the spirit of "modern" DFT, but still an excellent reference, with lucid description of the physics. 3. Slater, Adv. Quantum Chem. 6 (1972) 1 : describes "Slater's transition state (STS) method", where eigenvalues out of SCF calculations for configurations with non-integer occupation are used to approximate total energy differences. (might be a practical way of getting better estimates of true HOMO-LUMO excitation energies than straight orbital energy differences). 4. Williams et al.. J. Chem. Phys. 63 (1975) 628: a generalization and refinement of the STS method. 5. Janak, Phys. Rev. B 18 (1978) 7165: shows that eigenvalues eps_i are equal to partial derivatives of the total energy w.r.t. the occupation numbers for any XC functional (including of course the unknown exact XC): eps_i = del(E) / del(n_i) 6. Perdew and Zunger, Phys. Rev. B 23 (1981) 5048: discusses a serious shortcoming of the LDA and a remedy, the Self-Interaction Correction (SIC). In a scheme with SIC, the KS eigenvalues obtained are typically much closer to ionization potentials and electron affinities than in a LDA scheme. Following the PZ 1981 paper, there is a number of SIC papers showing this, search for authors Harrison and Whitehead. 7. Perdew and Levy, Phys. Rev. Lett. 51 (1983) 1884 : the title is "Physical content of the exact KS orbital energies: band gaps and derivative discontinuities." 8. Fritsche et al. has suggested a simple correction to orbital energy differences to get better estimates of excitation energies in solids but it is not clear if that "works" for small molecules. see L. Fritsche Physica B 172 (1991) 7 and possibly more recent papers by the same author. 9. In another context, Malkin et al. (J. Am. Chem. Soc. 116 (1994) 5898) proposed an equally simple, but very different, correction to orbital energy differences. Although they intended this correction to improve sum-over-states (SOS) expressions, it could be tried as improvement to the HOMO-LUMO energy difference. Related to this: The total energy can be written as a sum of eigenvalues (those of occupied orbitals) plus "other terms". These other terms have some qualitative meaning, therefore the sum of eigenvalues also has qualitative meaning, see 10. Gopinathan and Whitehead, Israel J. Chem. 19 (1980) 209 11. J. Harris, Int. J. Quantum Chem. 13 (1979) 189. There are more references, including some very recent work. I guess there is a lot more meaning to the KS eigenvalues than was believed some years ago and that there is still important things to be discovered, both on formal and numerical grounds. For your particular problem, many empirical schemes could be tried: straight orbital energy difference, STS, maybe some kind of empirical SIC (the correct SIC scheme is fairly complicated and compute-intensive), Fritsche's or Malkin's corrections. Regards, Rene Fournier fournier@physics.unlv.edu **************************************************************************** Dear Dr. Salzner; Dr. Levy of Tulane Univ. just presented a talk at the APS meeting on precisely the meaning of HOMO-LUMO Kohn-Sham orbital energy differences, and its relationship to the true excitation energy under certain assumptions. Unfortunately my scribbled notes are grossly incomplete, but here is a reference that you may want to check to learn about that: AUTHOR(s): Levy, Mel TITLE(s): Excitation energies from density-functional orbital energies. In: Physical review. A, Atomic, molecular, and opt DEC 01 1995 v 52 n 6 Page: R4313 Regards, Rene Fournier fournier@physics.unlv.edu From mbdtsnm@hpf.ch.man.ac.uk Wed Mar 27 10:19:05 1996 Received: from nessie.mcc.ac.uk for mbdtsnm@hpf.ch.man.ac.uk by www.ccl.net (8.7.1/950822.1) id JAA05399; Wed, 27 Mar 1996 09:56:13 -0500 (EST) Received: from hpf.ch.man.ac.uk (actually mchhpf.ch.man.ac.uk) by nessie.mcc.ac.uk with SMTP (PP); Wed, 27 Mar 1996 14:55:33 +0000 From: Nathaniel (noj) Malcolm Message-Id: <6866.9603271453@hpf.ch.man.ac.uk> Subject: cas freqs To: chemistry@www.ccl.net Date: Wed, 27 Mar 96 14:53:22 GMT Mailer: Elm [revision: 70.85] has anyone got experience of running CAS frequencies in g94, using basis sets that INCLUDE f-functions? I have been trying to run a 2 in 2 cas on f2 using the cc-pvtz basis, only 60 basis functions, this results in an error message : ------------------- The (ff|fd) Classes Not enough memory for any path: MxKBra= 1 MxKKet= 1 Memory= 1693664. After MaxDer, Avail=FFFFFFFFFFFFFFFFFFFFFFFFFFFFFTFFFFFFFFFFFFFFFFFFFF After MemPth, Avail=FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF After MxKxxx, Avail=FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF No path selected in FillAv. this was run on an hp-755 with 100Mb of memory but the same error occurs when run with 200Mb (on another machine)..... if i can avoid using numerical frequencies it would be nice.... thanks in advance Dr. Noj Malcolm Noj.Malcolm@man.ac.uk From owner-chemistry@ccl.net Wed Mar 27 12:19:06 1996 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.7.1/950822.1) id LAA08271; Wed, 27 Mar 1996 11:48:31 -0500 (EST) Received: from rccw21.rti.org for balbes@osiris.rti.org by bedrock.ccl.net (8.7.1/950822.1) id LAA17963; Wed, 27 Mar 1996 11:48:30 -0500 (EST) Received: from osiris.rti.org by RCCW21.RTI.ORG (PMDF V5.0-5 #11231) id <01I2TYXEH56O00Q8G1@RCCW21.RTI.ORG> for chemistry@ccl.net; Wed, 27 Mar 1996 11:48:22 -0500 (EST) Received: from [199.3.12.190] by osiris.rti.org via SMTP (931110.SGI/930416.SGI.AUTO) for @rccw21.rti.org:chemistry@ccl.net id AA22861; Wed, 27 Mar 1996 11:37:40 -0500 Date: Wed, 27 Mar 1996 11:39:49 -0500 (EST) From: "Lisa M. Balbes" Subject: Chemical Database Programs? To: chemistry@ccl.net Message-id: X-Mailer: VersaTerm Link v1.1.6 Content-transfer-encoding: 7BIT I have a friend who was using Unison (Tripos) to maintain a database of chemical structures with a Microsoft Access database. Unfortunately, that program has been discontinued, so she's looking for a replacement. Requirements are: IBM-PC compatible program, that will link through a macro to an existing MS Access database. They want to be able to do 2D and substructure searches, 3D would be nice but is not necessary. Compounds are industrial chemical (surfacants, lubricants), not large proteins. Any suggestions can be sent to me, balbes@osiris.rti.org, and I'll send a summary to her (as well as back to the list if there's interest). Thanks to all in advance, Lisa *** We don't care, we have each other, on the Internet. (Dave Barry) *** Lisa M. Balbes, Ph.D. Scientific Software Consulting Osiris Consultants (usability testing and technical writing) balbes@osiris.rti.org http://www.cris.com/~balbes From waite@cyclades.nrcps.ariadne-t.gr Wed Mar 27 16:19:09 1996 Received: from epmhs.gr for waite@cyclades.nrcps.ariadne-t.gr by www.ccl.net (8.7.1/950822.1) id PAA11124; Wed, 27 Mar 1996 15:52:09 -0500 (EST) Received: from isosun.ariadne-t.gr by epmhs.gr with SMTP id AA02155 (5.67a8/IDA-1.5 for ); Wed, 27 Mar 1996 22:34:18 +0200 Received: from cyclades (cyclades.nrcps.ariadne-t.gr) by isosun.ariadne-t.gr (4.1/SMI-4.0-MHS-6.0) id AA09853; Wed, 27 Mar 96 21:45:48 +0200 X-Ncc-Regid: gr.ariadnet Received: from localhost by cyclades (8.6.4/10.1) id WAA19508; Wed, 27 Mar 1996 22:52:33 +0200 Date: Wed, 27 Mar 1996 22:52:33 +0200 From: WAITE JOHN ( E.I.E ) Message-Id: <199603272052.WAA19508@cyclades> To: chemistry@www.ccl.net Subject: East Europe CCL indexes summaries available X-Charset: ELOT_928 X-Char-Esc: 29 Dear Netters, With Dr. Jan Labanowski's kind permission I announce the availability of the Computational Chemistry List's indexes summaries, mainly for use in Eastern Europe, from the FTP anonymous account at 143.233.245.4. cd pub/ccl In addition to index.YY, this contains README and help files. However the full indexes must still be obtained from OSC and NO search facilities are available in Athens. Dr. John Waite, e-mail: chem8@york.ac.uk or The National Hellenic Research Foundation, waite@cyclades.nrcps.ariadne-t.gr Organic and Pharaceutical Institute, phone: ++30-1-7238958 (direct) Vas. Konstantinou 48, phone: ++30-1-7247913(secrtry. Mary) Athens 116-35, fax: ++30-1-7247913 Greece or NCRS "Democritos", phone: ++30-1-6513112-5 X219 c/o Dr. G.Kordas, e-mail john@john.nrcps.ariadne-t.gr Material Science Institute, Aghia Paraskevi, Attikis, Athens 153-10, Greece From d3g359@fido.pnl.gov Wed Mar 27 18:19:07 1996 Received: from pnl.gov for d3g359@fido.pnl.gov by www.ccl.net (8.7.1/950822.1) id SAA12041; Wed, 27 Mar 1996 18:09:50 -0500 (EST) Received: from fido.pnl.gov by pnl.gov (PMDF V4.3-13 #6012) id <01I2U5Y53JA891W4I8@pnl.gov>; Wed, 27 Mar 1996 15:09:46 -0800 (PST) Received: by fido.pnl.gov (931110.SGI/930416.SGI.AUTO) for @relay.pnl.gov:CHEMISTRY@www.ccl.net id AA06965; Wed, 27 Mar 96 15:06:31 -0800 Date: Wed, 27 Mar 1996 15:06:31 -0800 From: d3g359@fido.pnl.gov (John Nicholas) Subject: solid state QM codes To: CHEMISTRY@www.ccl.net Message-id: <9603272306.AA06965@fido.pnl.gov> Content-transfer-encoding: 7BIT Hi, I'm interested in finding all quantum mechanical codes that can treat solid state (periodic systems). I'm familiar with crystal, embed, dsol. Please respond to me personally and if possible list any experiencs/impressions you have about the code, such as speed, ease-of-use, accuracy, etc. I will summarize for the list. Thanks, John ------------------------------------------------------------------------------ John Nicholas Office: (509) 375-6559 Senior Research Scientist FAX: (509) 375-6631 Environmental Molecular Sciences Laboratory Pacific Northwest National Laboratory Mailstop K1-96 Richland, WA 99352 ------------------------------------------------------------------------------ >From owner-chemistry@ccl.net Tue Mar 26 07:35 EST 1996 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.7.1/950822.1) id HAA14895; Tue, 26 Mar 1996 07:35:20 -0500 (EST) Received: from volta for aiba@ir.phys.chem.ethz.ch by bedrock.ccl.net (8.7.1/950822.1) id HAA21570; Tue, 26 Mar 1996 07:35:07 -0500 (EST) Date: Tue, 26 Mar 1996 13:34:58 +0200 Message-Id: <96032613345810@ir.phys.chem.ethz.ch> From: aiba@ir.phys.chem.ethz.ch (Ayaz Bakasov, Phys. Chem., ETH Zuerich (Zentrum)) To: chemistry@ccl.net Subject: small CHIRAL molecules - examples X-VMS-To: smtp%"chemistry@ccl.net" X-VMS-Cc: AIBA Content-Type: text Content-Length: 1255 Status: RO Dear fellow CCLers, just wanted to address your knowledge of small CHIRAL (no plane of symmetry or center of inversion) molecules. Trust you should know a lot! My knowledge of examples of small CHIRAL molecules is quite limited (I'm a theor. physicist): I am aware of H_2 O_2, S_2 H_2, N_2 O_4, some twisted geometries of hydrocarbons like C_2 H_2, C_2 H_4, C_2 H_6, etc. only. I wondered if you might have given more examples of such molecules, I am pretty sure there are lots of them. Desired stuff is that a molecule is not only CHIRAL (or has CHIRAL geometry in some of electronic states) but also that it is relatively stable, has volatile phase (i.e. it is in principle suitable for spectroscopy). I look for small molecules - then ab initio calculations on them are, in principle, more reliable. Lastly, references (fresh ones to trace work back) on the molecule-example would be most welcome. As I hope that the integral knowledge of the CCL community on the subject is vast, I am prepared to post a comprehensive summary of your responses. With kind regards, Ayaz Bakasov. ---------------------- Lab. fuer Phys. Chemie ETH-Zuerich (Zentrum) CH-8092 Zuerich Switzerland ---------------------- Phone: 0041-1-6327918 FAX: 0041-1-6321021 >From cheidel@weizen.mpibpc.gwdg.de Mon Mar 25 04:53 EST 1996 Received: from weizen.mpibpc.gwdg.de for cheidel@weizen.mpibpc.gwdg.de by www.ccl.net (8.7.1/950822.1) id EAA27158; Mon, 25 Mar 1996 04:53:43 -0500 (EST) Received: by weizen.mpibpc.gwdg.de (1.37.109.16/16.2) id AA125237612; Mon, 25 Mar 1996 10:53:32 +0100 Message-Id: <199603250953.EAA27158@www.ccl.net> Date: Mon, 25 Mar 1996 10:53:32 +0100 From: Christoph Heidelbach To: chemistry@www.ccl.net Subject: Summary: MD parameters from ab initio calculations Cc: cheidel@gwdg.de Content-Type: text Content-Length: 26071 Status: RO Dear CCL'ers, many thanks to all those who answered me. My original question was: I am searching for some information about the evaluation of force field parameters for molecular dynamics from ab initio or semiempirical calculations. What I am looking for is how to fit atomic charges and Lennard-Jones-parameters. Any answers will be greatly appreciated and I will summerize all replies. This is what I got: >From hinsenk@ERE.UMontreal.CA Tue Feb 27 22:04 MEZ 1996 Received: from harfang.CC.UMontreal.CA by weizen.mpibpc.gwdg.de with ESMTP (1.37.109.16/16.2) id AA206815086; Tue, 27 Feb 1996 22:04:46 +0100 Return-Path: Received: from eole.ERE.UMontreal.CA (eole.ERE.UMontreal.CA [132.204.10.20]) by harfang.CC.UMontreal.CA with ESMTP id QAA13932 (8.6.11/IDA-1.6 for ); Tue, 27 Feb 1996 16:03:35 -0500 Received: from cyclone.ERE.UMontreal.CA by eole.ERE.UMontreal.CA (950221.405.SGI.8.6.10/5.17) id QAA19296; Tue, 27 Feb 1996 16:03:34 -0500 Received: by cyclone.ERE.UMontreal.CA (950221.405.SGI.8.6.10/5.17) id QAA21209; Tue, 27 Feb 1996 16:03:34 -0500 Date: Tue, 27 Feb 1996 16:03:34 -0500 Message-Id: <199602272103.QAA21209@cyclone.ERE.UMontreal.CA> To: cheidel@weizen.mpibpc.gwdg.de In-Reply-To: <199602271757.MAA10086@www.ccl.net> (message from Christoph Heidelbach on Tue, 27 Feb 1996 18:57:05 +0100) Subject: Re: CCL:MD parameters from ab initio >From: hinsenk@ERE.UMontreal.CA (Konrad HINSEN) Status: RO I am searching for some information about the evaluation of force field parameters for molecular dynamics from ab initio or semiempirical calculations. What I am looking for is how to fit atomic charges and Lennard-Jones-parameters. Ich schreiben gerade an einem Artikel ueber ein solches Projekt (ein Potential fuer quantenmechanische Simulationen von Protonentransfer in Acetylaceton), mit einer recht ausfuehrlichen Abhandlung ueber das Fitten von Ladungen, da meine Methode sich von den ueblichen unterscheidet. Ich kann gerne eine Kopie (auch elektronisch) schicken, wenn alles fertig ist, d.h. voraussichtlich naechste Woche. ------------------------------------------------------------------------------- Konrad Hinsen | E-Mail: hinsenk@ere.umontreal.ca Departement de chimie | Tel.: +1-514-343-6111 ext. 3953 Universite de Montreal | Fax: +1-514-343-7586 C.P. 6128, succ. Centre-Ville | Deutsch/Esperanto/English/Nederlands/ Montreal (QC) H3C 3J7 | Francais (phase experimentale) ------------------------------------------------------------------------------- >From eduffy@laplace.csb.yale.edu Tue Feb 27 22:22 MEZ 1996 Received: from laplace.csb.yale.edu by weizen.mpibpc.gwdg.de with SMTP (1.37.109.16/16.2) id AA208516124; Tue, 27 Feb 1996 22:22:04 +0100 Return-Path: Received: from kepler by laplace.csb.yale.edu (NX5.67d/NX3.0M) id AA01528; Tue, 27 Feb 96 16:21:57 -0500 >From: "Erin Duffy" Received: (from eduffy@localhost) by kepler.csb.yale.edu (8.7.4/8.7.3) id QAA20313 for cheidel@weizen.mpibpc.gwdg.de; Tue, 27 Feb 1996 16:21:56 -0500 (EST) Message-Id: <199602272121.QAA20313@kepler.csb.yale.edu> Subject: Re: CCL:MD parameters from ab initio To: cheidel@weizen.mpibpc.gwdg.de (Christoph Heidelbach) Date: Tue, 27 Feb 1996 16:21:56 -0500 (EST) In-Reply-To: <199602271757.MAA10086@www.ccl.net> from "Christoph Heidelbach" at Feb 27, 96 06:57:05 pm X-Mailer: ELM [version 2.4 PL24] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Status: RO Hi - I'd suggest looking at some of Bill Jorgensen's papers - his group are experts in this area. Here is a small sampling. Please contact me if I can be of further assistance. - Erin Duffy eduffy@franklin.csb.yale.edu Jorgensen, W.L.; Madura, J.D.; Swenson, C.J. "Optimized Intermolecular Potential Functions for Liquid Hydrocarbons." J. Am. Chem. Soc., 1984, v.106, 6638-6646. Jorgensen, W.L.; Tirado-Rives, J. "The OPLS Potential Functions for Proteins. Energy Minimizations for Crystals of Cyclic Peptides and Crambin." J. Am. Chem. Soc., 1988, v.110, 1657-1666. Jorgensen, W.L.; Gao, J. "Cis-Trans Energy Difference for the Peptide Bond in the Gas Phase and in Aqueous Solution." J. Am. Chem. Soc., 1988, v.110, 4212. Jorgensen, W.L.; Severance, D.L. "Aromatic-Aromatic Interactions: Free Energy Profiles for the Benzene Dimer in Water, Chloroform, and Liquid Benzene." J. Am. Chem. Soc., 1990, v.112, 4768-4774. Duffy, E.M.; Severance, D.L.; Jorgensen, W.L. "Urea: Potential Functions, logP, and Free Energy of Hydration." Isr. J. Chem., 1993, v.33, 323-330. Carlson, H.A.; Nguyen, T.B.; Orozco, M.; Jorgensen, W.L. "Accuracy of Free Energies of Hydration for Organic Molecules from 6-31G(d)- Derived Partial Charges." J. Comput. Chem., 1993, v.14, 1240-1249. >From v_uk@iris23.biosym.com Wed Feb 28 02:05 MEZ 1996 Received: from bioc1.biosym.com by weizen.mpibpc.gwdg.de with SMTP (1.37.109.16/16.2) id AA225539529; Wed, 28 Feb 1996 02:05:29 +0100 Return-Path: Received: from iris23.biosym.com by bioc1.biosym.com (5.64/0.0) id AA21813; Tue, 27 Feb 96 17:09:46 -0800 Received: by iris23.biosym.com (940816.SGI.8.6.9/930416.SGI) for cheidel@weizen.mpibpc.gwdg.de id RAA27793; Tue, 27 Feb 1996 17:05:16 -0800 Date: Tue, 27 Feb 1996 17:05:16 -0800 >From: v_uk@biosym.com (Masahiko Katagari XPIRE 4-15-96 HOST John Newsam Tohoku University) Message-Id: <199602280105.RAA27793@iris23.biosym.com> To: cheidel@weizen.mpibpc.gwdg.de Subject: MD parameters Status: RO Dear Dr. Christoph Heidelbach, As for the parametrization, we (biosym/msi) parametrize the LJ and partial charge using a nonlinear least-squares fit to the ab-initio data. If you are interested in, please refer, e.g. J.Hill and J.Sauer, Molecular Mechanics Potential for Silica and Zeolite Catalysis Based on ab initio Calculations. 1. Dens and Microporous Silica J. Phys. Chem. 98, 1238 (1994). This method produces the potential which includes many body terms such as distortion. The charges in the forcefield are directly taken from a population analysis of the wavefunctions. The use of charges is somewhat artificial, since potential has its origin in a Taylor series expansion which accounts for all interactions. In this context, point charge interactions are not required, but because of the necessity to describe interactions between atoms or groups which are not directly connected by bonds, but which may come close to each other simulations, they are introduced in potential, too. Frankly speaking, we use the partial charge as a parameter to fit the experimental data. As for the repulsive van der Waals parameters, test particle method is frequently used. See for example, H. Bohm and R. Ahlrichs A Study of short-range repulsions. J. Chem. Phys., 77, 2028 (1982). or H. Bohm, R. Ahlrichs, P. Scharf and H. Schiffer Intermolecular potentials for CH4, CH3F, CHF3, CH3Cl, CH2Cl2, CH3CN and CO2 J. Chem. Phys., 81, 1389 (1984). Best Regards, Masa Katagiri __o__o_o__o __o Masahiko Katagiri __o__o_o__o __o `\<,\<,<,\<,`\<, v_uk@biosym.com `\<,\<,<,\<,`\<, O/ O/ O O/ OO/ O TEL -1-619-546-5389(direct) O/ O/ O O/ OO/ O FAX -1-619-458-0136 e_mail v_uk@biosym.com MSI 9685 Scranton Road San Diego, CA 92121 >From ross@cgl.ucsf.EDU Wed Feb 28 02:13 MEZ 1996 Received: from socrates.ucsf.EDU by weizen.mpibpc.gwdg.de with ESMTP (1.37.109.16/16.2) id AA225590020; Wed, 28 Feb 1996 02:13:40 +0100 Return-Path: Received: (from ross@localhost) by socrates.ucsf.EDU (8.7.3/GSC4.24) id RAA00603 for cheidel@weizen.mpibpc.gwdg.de; Tue, 27 Feb 1996 17:13:37 -0800 (PST) Date: Tue, 27 Feb 1996 17:13:37 -0800 (PST) >From: ross@cgl.ucsf.EDU Message-Id: <199602280113.RAA00603@socrates.ucsf.EDU> To: cheidel@weizen.mpibpc.gwdg.de Subject: Re: CCL:MD parameters from ab initio Status: RO You might want to check out the force field sections of the amber web pages at: http://www.amber.ucsf.edu/amber/ Bill Ross >From hebant@ext.jussieu.fr Wed Feb 28 09:21 MEZ 1996 Received: from shiva.jussieu.fr by weizen.mpibpc.gwdg.de with ESMTP (1.37.109.16/16.2) id AA256975685; Wed, 28 Feb 1996 09:21:25 +0100 Return-Path: Received: from idf.ext.jussieu.fr (idf.ext.jussieu.fr [134.157.81.129]) by shiva.jussieu.fr (8.7.3/jtpda-5.2) with ESMTP id JAA20491 ; Wed, 28 Feb 1996 09:20:47 +0100 (MET) Received: from [134.157.11.16] by idf.ext.jussieu.fr (8.6.10/jtpda-4.0) with SMTP; Wed, 28 Feb 1996 09:20:43 +0100 X-Sender: hebant@idf.ext.jussieu.fr Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 28 Feb 1996 09:19:25 +0100 To: Christoph Heidelbach , chemistry@www.ccl.net >From: hebant@ext.jussieu.fr (Pascal HEBANT) Subject: Re: CCL:MD parameters from ab initio Cc: cheidel@gwdg.de Status: RO At 18:57 27/02/96, Christoph Heidelbach wrote: >Hallo everybody out there, > >I am searching for some information about the evaluation of force field >parameters for molecular dynamics from ab initio or semiempirical calculations. >What I am looking for is how to fit atomic charges and >Lennard-Jones-parameters. >Any answers will be greatly appreciated and I will summerize all replies. > >Best regards. > >Christoph > We have done something like that in our lab : we have computed pair potential function of Born Huggins Mayer type with DMol calculations : Point energies are performed for the 2 atoms involved in the potential with fixed geometry. Then, a curve fitting (with Kaleidagraph) allowed us to obtain the parameters. See e.g. Roullet, G., J. J. Legendre, et al. (1994). "Ab-initio and molecular dynamics studies of molten NaCl Graphite interfaces." Molten Salt Forum 1-2: 105-116. Hope this helps you Pascal ***************************************************************************** Pascal HEBANT Laboratoire d'Electrochimie et de Chimie Analytique Ecole Nationale Superieure de Chimie de Paris 11 rue Pierre et Marie Curie 75005 Paris FRANCE tel: 33 (1) 44 27 66 94 fax: 33 (1) 44 27 67 50 http://alcyone.enscp.jussieu.fr/Pages/LECA/Electrochimie.html ***************************************************************************** >From ferenc@rchsg8.chemie.uni-regensburg.de Wed Feb 28 09:50 MEZ 1996 Received: from comsun.rz.uni-regensburg.de by weizen.mpibpc.gwdg.de with SMTP (1.37.109.16/16.2) id AA262597400; Wed, 28 Feb 1996 09:50:00 +0100 Return-Path: Received: from rchsg8.chemie.uni-regensburg.de by comsun.rz.uni-regensburg.de with SMTP id AA19403 (5.65c/IDA-1.4.4 for ); Wed, 28 Feb 1996 09:49:57 +0100 Received: by rchsg8.chemie.uni-regensburg.de (931110.SGI/URRZ-Sub-1.5-irix) (for cheidel@weizen.mpibpc.gwdg.de) id AA14032; Wed, 28 Feb 96 09:50:12 +0100 >From: "Ferenc Molnar" Message-Id: <9602280950.ZM14030@rchsg8.chemie.uni-regensburg.de> Date: Wed, 28 Feb 1996 09:50:11 +0100 In-Reply-To: Christoph Heidelbach "CCL:MD parameters from ab initio" (Feb 27, 6:57pm) References: <199602271757.MAA10086@www.ccl.net> X-Mailer: Z-Mail (3.1.0 22feb94 MediaMail) To: Christoph Heidelbach Subject: Re: CCL:MD parameters from ab initio Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 Status: RO Hallo Chrisoph! > What I am looking for is how to fit atomic charges and > Lennard-Jones-parameters. > Any answers will be greatly appreciated and I will summerize all replies. Das wuerde mich auch sehr interessieren! Bitte schick mir doch die Antworten, insbesondere Hinweise auf bestehende Programme! Einige Referenzen kann ich dir geben: 1) N.L. Allinger and J.P. Bowen in Rev.Comp.Chem. 2, K.B. Lipkowitz and D.B. Boyd (Eds.), VCH, 1991, ISBN 3-527-28338-2. 2) U. Dinur and A.T. Hagler (ebd.). 3) AUTHOR = {G. Chalasi\'nski and M.M. Szcze\'sniak}, TITLE = {Origins of Structure and Energetics of van der Waals JOURNAL =Chem. Rev., YEAR = {1994}, VOLUME = {94}, NUMBER = {7}, PAGES = {1723--1765}, KEYS = {van der Waals, ab initio, dispersion, correlation, PES}, 4) AUTHOR = {J.R. Maple and M.-J. Hwang and T.P. Stockfisch and U. Dinur and M. Waldman and C.S. Ewig and A.T. Hagler}, TITLE = {Derivation of Class II Force Fields. I. Methodology and Quantum Force Field for the Alkyl Functional Group and Alkane Molecules}, JOURNAL =J. Comp. Chem., YEAR = {1994}, VOLUME = {15}, NUMBER = {2}, PAGES = {162--182}, KEYS = {derivatives, parameters, ab initio, PES, anharmonicity, intramolecular forces, cross terms, transferability, validity }, Clusters from ab Initio Calculations}, 5) AUTHOR = {D.E. Woon}, TITLE = {Accurate modeling of intermolecular forces: a systematic M\o ller-Plesset study of the argon dimer using correlation consistent basis sets}, JOURNAL = Chem. Phys. Lett., YEAR = {1993}, VOLUME = {204}, NUMBER = {1,2}, PAGES = {29--35}, KEYS = { PES, MP4, augmented correlation consistent basis set, argon, supermolecule approach, BSSE, CP}, Ich habe auch schon einige Parametrisierungsversuche unternommen. Allerdings geraet man sehr schnell an die Grenzen der ab initio Prgramme (Gaussian, Gamess) oder der Optimierungsverfahren (zu viele Parameter). Eine Parametrisierung kann selbst fuer kleine Systeme sehr aufwendig werden! Trotzdem: Have fun! Ferenc >From chemistry-request@www.ccl.net Wed Feb 28 10:07 MEZ 1996 Received: from www.ccl.net by weizen.mpibpc.gwdg.de with ESMTP (1.37.109.16/16.2) id AA263458467; Wed, 28 Feb 1996 10:07:47 +0100 Return-Path: Received: for chemistry-request@www.ccl.net by www.ccl.net (8.7.1/950822.1) id DAA20495; Wed, 28 Feb 1996 03:32:24 -0500 (EST) Received: from shiva.jussieu.fr for hebant@ext.jussieu.fr by www.ccl.net (8.7.1/950822.1) id DAA20463; Wed, 28 Feb 1996 03:21:10 -0500 (EST) Received: from idf.ext.jussieu.fr (idf.ext.jussieu.fr [134.157.81.129]) by shiva.jussieu.fr (8.7.3/jtpda-5.2) with ESMTP id JAA20491 ; Wed, 28 Feb 1996 09:20:47 +0100 (MET) Received: from [134.157.11.16] by idf.ext.jussieu.fr (8.6.10/jtpda-4.0) with SMTP; Wed, 28 Feb 1996 09:20:43 +0100 X-Sender: hebant@idf.ext.jussieu.fr Message-Id: Date: Wed, 28 Feb 1996 09:19:25 +0100 To: Christoph Heidelbach , chemistry@www.ccl.net >From: hebant@ext.jussieu.fr (Pascal HEBANT) Subject: CCL:MD parameters from ab initio Cc: cheidel@gwdg.de Sender: Computational Chemistry List Errors-To: ccl@www.ccl.net Precedence: bulk Status: RO At 18:57 27/02/96, Christoph Heidelbach wrote: >Hallo everybody out there, > >I am searching for some information about the evaluation of force field >parameters for molecular dynamics from ab initio or semiempirical calculations. >What I am looking for is how to fit atomic charges and >Lennard-Jones-parameters. >Any answers will be greatly appreciated and I will summerize all replies. > >Best regards. > >Christoph > We have done something like that in our lab : we have computed pair potential function of Born Huggins Mayer type with DMol calculations : Point energies are performed for the 2 atoms involved in the potential with fixed geometry. Then, a curve fitting (with Kaleidagraph) allowed us to obtain the parameters. See e.g. Roullet, G., J. J. Legendre, et al. (1994). "Ab-initio and molecular dynamics studies of molten NaCl Graphite interfaces." Molten Salt Forum 1-2: 105-116. Hope this helps you Pascal ***************************************************************************** Pascal HEBANT Laboratoire d'Electrochimie et de Chimie Analytique Ecole Nationale Superieure de Chimie de Paris 11 rue Pierre et Marie Curie 75005 Paris FRANCE tel: 33 (1) 44 27 66 94 fax: 33 (1) 44 27 67 50 http://alcyone.enscp.jussieu.fr/Pages/LECA/Electrochimie.html ***************************************************************************** -------This is added Automatically by the Software-------- -- Original Sender Envelope Address: hebant@ext.jussieu.fr -- Original Sender From: Address: hebant@ext.jussieu.fr CHEMISTRY@www.ccl.net: Everybody | CHEMISTRY-REQUEST@www.ccl.net: Coordinator MAILSERV@www.ccl.net: HELP CHEMISTRY or HELP SEARCH | Gopher: www.ccl.net 73 Anon. ftp: www.ccl.net | CHEMISTRY-SEARCH@www.ccl.net -- archive search Web: http://www.ccl.net/chemistry.html >From Darren.Andrews@man.ac.uk Wed Feb 28 11:34 MEZ 1996 Received: from nessie.mcc.ac.uk by weizen.mpibpc.gwdg.de with ESMTP (1.37.109.16/16.2) id AA273343675; Wed, 28 Feb 1996 11:34:35 +0100 Return-Path: Received: from [130.88.12.235] (actually femt03.ch.man.ac.uk) by nessie.mcc.ac.uk with SMTP (PP); Wed, 28 Feb 1996 10:34:01 +0000 X-Sender: mbcdpa@nessie.mcc.ac.uk Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 28 Feb 1996 10:38:40 +0000 To: cheidel@weizen.mpibpc.gwdg.de >From: Darren.Andrews@man.ac.uk (Darren Andrews) Subject: Re: CCL:MD parameters from ab initio Status: RO A very basic way to do this would be to use the Mulliken or similar charges >from the Ab Initio output and some empirical Lennard-Jones parameters e.g., Lorentz-Berthelot to get a pretty rough set of starting values. If you use a distributed multipole analysis approach (see Anthony Stone circa. '89) which can be calculated using CADPAC you can get a (very) good approximation of the electrostatic part of the interaction. If the system you are looking at is dominated by electrostatic forces then the empirical L-J parameters will be less important. Darren Andrews. University of Manchester, Department of Chemistry, Oxford road, Manchester. M13 9PL. Darren.Andrews@man.ac.uk PGP: 512/62A971A9 Tel: 0161 275 2000 ext.4699. Fax: 0161 275 4598. >From garciae@guarany.cpd.unb.br Wed Feb 28 13:33 MEZ 1996 Received: from guarany.cpd.unb.br by weizen.mpibpc.gwdg.de with SMTP (1.37.109.16/16.2) id AA285770809; Wed, 28 Feb 1996 13:33:29 +0100 Return-Path: Received: by guarany.cpd.unb.br (AIX 3.2/UCB 5.64/4.03) id AA62884; Wed, 28 Feb 1996 09:32:46 -0300 Date: Wed, 28 Feb 1996 09:32:46 -0300 (GRNLNDST) >From: edgardo garcia To: Christoph Heidelbach Subject: Re: CCL:MD parameters from ab initio In-Reply-To: <199602271757.MAA10086@www.ccl.net> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Status: RO Hi Christoph, CHARGES I'm currently using AM1 CHELP Potential derived charges that reproduce the molecular dipoles with 12% error, usually bigger dipoles. The dipoles are similar to the ones obtained from 6-31G* on the same compounds. I also tried Charge Equilibration Method of Antony Rappe but the results are really bad, not only the dipoles are wrong in absolute values but the trends for a set of molecules is also wrong. The AM1 dipole trends are also correct. The problem with force fields is that you need fixed charges, now charges change with the connectivity environment and also (but much less important) with the 3D environment. I use AM1 charges computed for model compounds and then I symmetrize the charges, by a simple average of the values of topologicaly identical atoms. With this fixed 2D AM1 CHELP charges I then parametrize the Force Field to reproduce energy data. There is no point in trying to be more accurate on that unless you can use hyper-atom-types that embody the atom molecular environment. VdW The vdW parameters are another story :-( I don't really know what is a good method. The points are: - what do you want ? - what is the quality/cost ratio for the method ? Is is worth it ? I'm using OPLS vdW parameters and they are fixed for specific atom types. >From my point of view one of the most serius works for liquid phases. Again for organic molecules, I bet you that the vdW parameters will change a bit depending on the atom environment. It could be that some ab initio procedure can give you a good functional form and good parameters, considering the BSSE was removed, but the problem is : can you really make use of this great accuracy in your force field ? You have to consider that force fields use limited atom types and also there are the vdW combination rules, ad hoc little formulas, who know were they really work ? There is a nice work for noble gases for the ab initio derivation of vdW parameters, functional forms and combination rules. I don't remember the reference now but I can give it to you latter if you are interested. The author is A.T. Hagler from Merk, I think it was on JACS, 1985 - 1993. The big deal will be to find parameters that are independent of the environment, i.e., pure parameteres. The big problem is what are good functional forms, how the parameters change with topological and with 3D environment and how to include this in a usefull Force Field that is able to handdle them to make practical and accurate predictions. Hope this helps, Edgardo Dr.Edgardo Garcia Dpto of Chemistry University of Brasilia, Brasilia DF, Brazil >From cheidel@gwdg.de Thu Feb 29 16:53 MEZ 1996 Received: from gwdu42.gwdg.de by weizen.mpibpc.gwdg.de with SMTP (1.37.109.16/16.2) id AA140329197; Thu, 29 Feb 1996 16:53:17 +0100 Return-Path: Received: from gwdu28.gwdg.de (actually gwdu28-eth.gwdg.de) by gwdu42.gwdg.de with SMTP (PP); Thu, 29 Feb 1996 16:52:44 +0100 Received: by gwdu28.gwdg.de; (5.65v3.2/1.1.8.2/19Jan96-1057AM) id AA08694; Thu, 29 Feb 1996 16:52:42 +0100 >From: cheidel Message-Id: <9602291552.AA08694@gwdu28.gwdg.de> Subject: Re: CCL:MD parameters from ab initio (fwd) To: cheidel@weizen.mpibpc.gwdg.de Date: Thu, 29 Feb 1996 16:52:41 +0100 (MET) X-Mailer: ELM [version 2.4 PL25] Content-Type: text Content-Length: 3637 Status: RO Forwarded message: >From jxh@ibm12.biosym.com Wed Feb 28 23:30:32 1996 Delivery-Date: Wed, 28 Feb 1996 23:30:32 +0100 Message-Id: Date: Wed, 28 Feb 1996 14:25:37 -0800 (PST) >From: Joerg Hill To: cheidel@gwdg.de Subject: Re: CCL:MD parameters from ab initio Hallo, > I am searching for some information about the evaluation of force field > parameters for molecular dynamics from ab initio or semiempirical calculations. > What I am looking for is how to fit atomic charges and Lennard-Jones-parameters. > Any answers will be greatly appreciated and I will summerize all replies. Es gibt eine ganze Serie von Arbeiten ueber die Ableitung von repulsiven van-der-Waals-Parametern aus ab initio Rechnungen von Boehm und Ahlrichs: @article{boe82, author={H.-J.~B{\"o}hm and R.~Ahlrichs}, title={A study of short--range repulsions}, journal={J. Chem. Phys.}, year=1982, volume=77, pages=2028 } @article{boe84:1, author={H.-J.~B{\"o}hm and R.~Ahlrichs and P.~Scharf and H.~Schiffer}, title={Intermolecular potentials for {CH$_4$, CH$_3$F, CHF$_3$, CH$_3$Cl, CH$_2$Cl$_2$, CH$_3$CN, and CO$_2$}}, journal={J. Chem. Phys.}, year=1984, volume=81, pages=1389 } @article{sag87, author={K.~P.~Sagarik and R.~Ahlrichs}, title={A test particle model potential for formamide and molecular dynamics simulations of the liquid}, journal={J. Chem. Phys.}, year=1987, volume=86, pages=5117 } @article{sag86:1, author={K.~P.~Sagarik and R.~Ahlrichs and S.~Brode}, title={ }, journal={Mol. Phys.}, year=1986, volume=57, pages=1247 } @article{boe84:2, author={H.-J.~B{\"o}hm and C.~Meissner and R.~Ahlrichs}, title={ }, journal={Mol. Phys.}, year=1984, volume=53, pages=651 } @article{sag86:2, author={K.~P.~Sagarik and R.~Ahlrichs}, title={ }, journal={Chem. Phys. Letters}, year=1986, volume=131, pages=74 } Ich selbst habe vor kurzem ein Paper bei J. Comp. Chem. eingereicht, in dem auch die dispersiven Parameter aus ab initio Rechnungen abgeleitet werden. Ich hoffe, das ich bald Nachricht ueber die Annahme bekomme. Viele Gruesse nach Deutschland Joerg-R. Hill ------------------------------------------------------------------------------- - Dr. Joerg-Ruediger Hill | Every attempt to employ mathematical methods in the Biosym/MSI | study of chemical questions must be considered pro- 9685 Scranton Road | foundly irrational and contrary to the spirit of San Diego, CA 92121-2777 | chemistry ... If mathematical analysis should ever USA | hold a prominent place in chemistry - an aberration | which is happily almost impossible - it would Phone (619) 546-5508 | occasion a rapid and widespread degeneration of Fax (619) 458-0136 | that science. E-mail jxh@biosym.com | Auguste Comte, Philosophie Positive, Paris, 1838 ------------------------------------------------------------------------------- - The opinions expressed in this message are my personal opinions and no offical statements of Biosym Technologies, Inc. For informations about Biosym products take a look at: http://www.msi.com/. ------------------------------------------------------------------------------- - >From jmanrique@beilstein.com Mon Mar 25 08:06 EST 1996 Received: from news.ossinc.net for jmanrique@beilstein.com by www.ccl.net (8.7.1/950822.1) id IAA29683; Mon, 25 Mar 1996 08:06:24 -0500 (EST) Received: from NULL (ad31-153.compuserve.com [199.174.134.153]) by news.ossinc.net (8.6.12/8.6.9) with SMTP id HAA09447; Mon, 25 Mar 1996 07:08:49 -0700 Date: Mon, 25 Mar 1996 07:08:49 -0700 Message-Id: <199603251408.HAA09447@news.ossinc.net> X-Sender: jmanrique@mail.beilstein.com X-Mailer: Windows Eudora Light Version 1.5.2 Mime-Version: 1.0 To: chemistry@www.ccl.net From: Jorge Manrique Subject: Press Release Content-Type: text/plain; charset="us-ascii" Content-Length: 1306 Status: RO For Immediate Release Editorial Contact: Jorge Manrique Beilstein Information Systems (415) 358-9091 jmanrique@beilstein.com Paul Collins Digital Equipment Corporation (508) 467-2251 paul.collins@mro.mts.dec.com Beilstein Information Systems Announces CrossFire Running on Digital's AlphaServer Family New Orleans, LA., March 25, 1996 -- Beilstein Information Systems and Digital Equipment Corporation announced today a partnership that will develop and market solutions to address the needs of the research chemist and chemical information specialist. The first development to come out of the new partnership will be Beilstein's CrossFire running across the Digital AlphaServer product family on Digital's OpenVMS and Digital UNIX platforms. The Alpha CrossFire Server, which will be available in the Summer of 1996, will deliver a new avenue for access to the Beilstein Database, the world's largest and most accurate collection of information on organic chemical compounds. ______________________________________________________ For more details, please point your browser to: http://www.beilstein.com/press.html Jorge Manrique Director of Marketing Beilstein Information Systems, Inc. jmanrique@beilstein.com Phone: 415.358.9091 Fax: 415.358.9099