From owner-chemistry@ccl.net Thu Nov 30 06:54:18 1995 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.6.10/950822.1) id GAA01387; Thu, 30 Nov 1995 06:42:59 -0500 Received: from cbdcom.apgea.army.mil for grfamini@cbdcom.apgea.army.mil by bedrock.ccl.net (8.7.1/950822.1) id GAA00715; Thu, 30 Nov 1995 06:42:56 -0500 (EST) Date: Thu, 30 Nov 95 6:41:22 EST From: George R Famini To: chemistry@ccl.net Subject: Preliminary COMP Program for New Orleans Organization: International Programs Office Priority: Normal Message-ID: <9511300641.aa06383@cbdcom.apgea.army.mil> Well folks, I have pretty much finished putting together the symposia for the Division of Computers in Chemistry (COMP) program for the New Orleans American Chemical Sociey meeting (end of March 1996). Below is the preliminary agenda, representing only the listing of when the symposia will happen. As always, I reserve the right to change the times of the symposia (or cancel one or more) without notice. But, this is the schedule we will attempt to adhere to. All of the symposia look to be very interesting, I will post a complete program (with paper titles) in a few weeks. Of special note is the Computers in Chemistry award symposium, honoring Norman Allinger. If you have any questions concerning the schedule for New Orleans, please do not hesitate to contact me. George R. Famini COMP Program Chair 211th ACS National Meeting, New Orleans, LA DUE DATE: December 18,1995 DIVISION OR COMMIDivision of Computers In Chemistry PROGRAM CHAIRPERSG. R. Famini, US Army Edgewood RD&E Center, Aberdeen Prvg Gd, MD Poster Estimated seating Session Title Cosponsor Session: Key ing Time & # Speakers SUNDAY, MARCH 24 - AM A.Computational Chemistry Assisted 250 Drug Discovery B.Monte Carlo Methods in 200 Chemistry SUNDAY, MARCH 24 - PM A.Computational Chemistry Assisted 250 Drug Discovery B.Monte Carlo Methods in 200 Chemistry C.Physical/Chemical Property 200 Prediction MONDAY, MARCH 25 - AM A.Computational Chemistry Assisted 250 Drug Discovery B.Monte Carlo Methods in 200 Chemistry C.Physical/Chemical Property 200 Prediction MONDAY, MARCH 25 - PM A.Computational Chemistry Assisted 250 Drug Discovery B.Experimental Methods for Division of 150 CHemical Models Analytical Chemistry C.Physical/Chemical Property 200 Prediction MONDAY, MARCH 25 - EVE Sci-Mix 8:00 PM 11 TUESDAY, MARCH 26 - AM A.Computers in Chemistry Award 250 Symposium Honoring Norman L. Allinger B.Experimental Methods for 150 Chemical Models TUESDAY, MARCH 26 - PM A.Computational Chemistry Assisted 250 Drug Discovery B.Molecular Modeling Applications Division of 200 to Environmental Problems Environmental Chemistry Inc C.Frugal Chemist's Software Division of 200 Chemical Information TUESDAY, MARCH 26 - EVE A.General Poster Session 7:00 PM 33 WEDNESDAY, MARCH 27 - AM A.Semi-Empirical Methods: Is Division of 200 There a Future? Physical Chemistry B.Molecular Modeling Applications 200 to Environmental Problems WEDNESDAY, MARCH 27 - PM A.Semi-Empirical Methods: Is 200 There a Future? B.Molecular Modeling Applications 200 to Environmental Problems THURSDAY, MARCH 28 - AM A.Semi-Empirical Methods: Is 200 There a Future? B.General Oral 100 THURSDAY, MARCH 28 - PM A.Semi-Empirical Methods: Is 150 There a Future? B.General Oral 100 From owner-chemistry@ccl.net Thu Nov 30 09:24:20 1995 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.6.10/950822.1) id JAA02746; Thu, 30 Nov 1995 09:16:59 -0500 Received: from flowbee.interaccess.com for ljs@interaccess.com by bedrock.ccl.net (8.7.1/950822.1) id JAA02113; Thu, 30 Nov 1995 09:16:57 -0500 (EST) Received: from d109.lib.interaccess.com (d109.lib.interaccess.com [204.149.98.109]) by flowbee.interaccess.com (8.7.2/8.6.9) with SMTP id IAA00646 for ; Thu, 30 Nov 1995 08:06:57 -0600 (CST) Message-Id: <199511301406.IAA00646@flowbee.interaccess.com> X-Sender: ljs@pop.interaccess.com X-Mailer: Windows Eudora Version 1.4.4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 29 Nov 1995 08:16:17 -0600 To: chemistry@ccl.net From: ljs@interaccess.com (Louis J. Sharp IV) Subject: Hyperchem Is anyone out there using Hyperchem for modelling of polymer systems? I would be interested in knowing about it and would like to discuss some of my ideas on this. Lou Sharp ========================================================================== Dr. Louis J. Sharp IV Director Scientific Affairs Dexter Packaging Products Phone (708)623-4200 ext 4418 email ljs@interaccess.com ========================================================================== From cwm@proteus.co.uk Thu Nov 30 10:24:21 1995 Received: from eros.britain.eu.net for cwm@proteus.co.uk by www.ccl.net (8.6.10/950822.1) id KAA03841; Thu, 30 Nov 1995 10:17:17 -0500 Received: from proteus.co.uk by eros.britain.eu.net with UUCP id ; Thu, 30 Nov 1995 15:11:30 +0000 Received: from ivory.proteus.co.uk by iliad.proteus.co.uk; Thu, 30 Nov 1995 15:03:15 GMT From: Chris Murray Message-Id: <9511301503.ZM13936@Ivory.proteus.co.uk> Date: Thu, 30 Nov 1995 15:03:56 +0000 X-Mailer: Z-Mail (3.2.0 26oct94 MediaMail) To: chemistry@www.ccl.net Subject: Synthetic Accessibility Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Hi all, When designing new molecules in drug discovery projects, an important consideration is the synthetic feasibility of the molecules. This is a somewhat different question than programs like LHASA address since they seem to concentrate on suggesting synthesis routes. Does anybody have information or experience of synthetic feasibility programs? References to papers describing the programs appear to be few and far between. I will summarise to the net if there is any interest. chris -- Chris Murray | Proteus Molecular Design Ltd., | Tel: 01625-500555 Lyme Green Business Park, | Fax: 01625-500666 Macclesfield, Cheshire, | Email: C.W.Murray@proteus.co.uk SK11 0JL, UK | From owner-chemistry@ccl.net Thu Nov 30 10:54:21 1995 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.6.10/950822.1) id KAA04327; Thu, 30 Nov 1995 10:53:20 -0500 Received: from uibk.ac.at for Michael.Probst@uibk.ac.at by bedrock.ccl.net (8.7.1/950822.1) id KAA03161; Thu, 30 Nov 1995 10:53:11 -0500 (EST) Received: from dm.uibk.ac.at (dme.uibk.ac.at) by uibk.ac.at with SMTP id AA26487 (5.65c/IDA-1.4.4 for ); Thu, 30 Nov 1995 16:52:57 +0100 Received: from mp3-c724 by dm.uibk.ac.at (950911.SGI.8.6.12.PATCH825/CFIBK-2f.IRIX) id QAA21571; Thu, 30 Nov 1995 16:52:58 +0100 Message-Id: <199511301552.QAA21571@dm.uibk.ac.at> Comments: Authenticated sender is From: "Michael Probst" To: chemistry@ccl.net Date: Thu, 30 Nov 1995 16:53:01 +0000 Subject: g94 compound freq+opt Reply-To: michael.probst@uibk.ac.at Cc: c72417@dm.uibk.ac.at Priority: normal X-Mailer: Pegasus Mail for Windows (v2.01) Dear Gaussian - experts: The following input: ----------------------------------------------- #P BLYP/aug-cc-pVTZ SCF=DIRECT OPT=Z-MATRIX FREQ MAXDISK=13000000 NITRAT:aug-cc-pVTZ -1 1 N1 O2 1 RONN O3 1 RONN 2 AOON O4 1 RONN 2 AOON 3 TORS 0 Variables: RONN=1.271 Constants: AOON=120. TORS=180. ------------------------------------ seems to work well but upon cloeser looking there is a large energy difference between the energy at the end of the optimization (-280.470491943) and the energy calculated in the frequency step (-280.446822509). I would not expect the NO3- ion to behave that way and further, if I make a independent frequency calculation with the optimized N-O distance (1.280612 Angstroem) I get the same energy as in the optimization job (and, of course, different frequencies as in the compound job) Can somebody tell me the reason for the differences in the job with freq and opt together ? Thanks a lot ! Michael --------------------------------------------------------------------------- Michael Probst Internet: michael.probst@uibk.ac.at Department of Inorganic Chemistry Fax: ++43(512)507 2934 Innsbruck University Tel: ++43(512)507 5153 Innrain 52a Austria From rochus@felix.anorg.chemie.tu-muenchen.de Tue Nov 28 08:00:00 1995 Received: from felix.anorg.chemie.tu-muenchen.de for rochus@felix.anorg.chemie.tu-muenchen.de by www.ccl.net (8.6.10/950822.1) id HAA20717; Tue, 28 Nov 1995 07:53:17 -0500 Received: by felix.anorg.chemie.tu-muenchen.de (940816.SGI.8.6.9/930416.SGI) id NAA23910; Tue, 28 Nov 1995 13:51:27 +0100 From: "Rochus Schmid" Message-Id: <9511281351.ZM23908@felix> Date: Tue, 28 Nov 1995 13:51:26 +0100 To: chemistry@www.ccl.net Subject: Free energy calculation Cc: rochus@felix.anorg.chemie.tu-muenchen.de Dear Netters: I'm new in that field and I have some questions concerning the calculation of free energies of sissociation. I have a molecule like this: A2 B3 \ / A1---B1---B2 / \ A3 B4 I want to get the free energy of dissociation of bond A1-B1. My potential energy function is a classical forcefield and the bond A1--B1 is parametrized via QM-calculations (also the change in the forcefield of the fragments A and B upon dissociation is parametrized analytically). David A. Pearlman (J. Chem. Phys. 1993, 98, 8946) suggest thermodynamic integration to be the method of coice. If I understood it correctly, I have to sum up the components of the cartesian forces on all atoms along the vector >from A1 to B1 (with oposite signs for the fragments A and B) and integrate the over the distance between A1 and B1. My problem are the internal degrees of freedom, which will be "converted" to rotational and translational degrees of freedom if the coupling parameter lambda reaches 1 (complete dissociation). I guess, it will take more and more sampling for increasing lambda. And there must be a point, where it is not longer reasonable. What to do then? Are there any tricks to make life easier? Any hints? I would appreciate every comment on this. Thank you very much in advance. I will summarize to the net. Greetings, Rochus -- ******************************************************************************** Rochus Schmid Technische Universitaet Muenchen Tel. ++49 89 3209 3140 Anorganisch Chemisches Institut 1 Fax. ++49 89 3209 3473 Prof. W. A. Herrmann E-mail: Lichtenbergstrasse 4 rochus@felix.anorg.chemie.tu-muenchen.de 85747 Garching ******************************************************************************** From owner-chemistry@ccl.net Tue Nov 28 13:03:59 1995 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.6.10/950822.1) id NAA26914; Tue, 28 Nov 1995 13:03:58 -0500 Received: from bioc1.biosym.com for mjf@iris120.biosym.com by bedrock.ccl.net (8.7.1/950822.1) id NAA03156; Tue, 28 Nov 1995 13:03:43 -0500 (EST) Received: from iris120.biosym.com by bioc1.biosym.com (5.64/0.0) id AA25503; Tue, 28 Nov 95 10:02:39 -0800 Received: by iris120.biosym.com (940816.SGI.8.6.9/930416.SGI) for chemistry@ccl.net id KAA01618; Tue, 28 Nov 1995 10:03:11 -0800 Date: Tue, 28 Nov 1995 10:03:11 -0800 From: mjf@biosym.com (Mark J Forster ) Subject: Chemical Shift and Shielding Calculations Message-Id: <199511281803.KAA01618@iris120.biosym.com> To: chemistry@ccl.net Subject: Chemical Shift and Shielding Calculations. Seiji Mori asked the following question: > Dear Sirs, > > I posted to CCL about the methods of NMR calculation a fey days ago , and > had an other question. > In G94, I tried to calculate the chemical shifts , there are magnetic > shieldings snip... > Would you please tell me the physical meaning of isotropic and anitrosopy, > and which is an equivalent of the experimental chemical shift? It is better > that > you show the references. > > Sincerely yours, > Seiji Mori email:smori@chem.s.u-tokyo.ac.jp The property calculated by an ab initio shielding scheme is typically a nuclear magnetic shielding tensor in the form of a 3x3 matrix. In physical terms the elements of the tensor represent the shielding along x,y and z when the applied magnetic field is along x,y and z in turn. This matrix may then be separated into symmetric and antisymmetric components, when the former is diagonalised then one obtains the three principal components of the shielding tensor denoted sigma(1,1) sigma(2,2) and sigma(3,3) with the convention sigma(3,3) >= sigma(2,2) >= sigma(1,1) the isotropic part of the shielding tensor is the trace or average of these three components and represents the value expected for an atom in a molecule that tumbles rapidly and isotropically. trace = ( sigma(1,1) + sigma(2,2) + sigma(3,3)) /3 In non isotropic systems such as single crystals or oriented liquid crystals the shielding takes on an orientational dependence. The shielding anisotropy is defined as anisotropy = sigma(3,3) - ( sigma(1,1)+sigma(2,2) )/2 and is a measure of the deviation of the shielding from spherical symmetry. For heavier nuclei the shielding anisotropy can be large (eg > 5000 ppm in 199Hg and 205Tl compounds) and this can often be a significant mechanism for nuclear spin relaxation. In addition the shielding asymmetry may be defined as asymmetry = (sigma(2,2)-sigma(1,1) ) / (sigma(3,3) -trace) An axially symmetric shielding tensor has a non zero anisotropy but a zero value for the asymmetry. The chemical shift measured by NMR is the difference between the shielding tensors for a nucleus in the compound under study and in the reference compound (typically TMS for 1H, 13C and 29Si). So to compare ab initio computed shielding with experimental chemical shifts two calculations will need to be performed one for the molecule under study and one for the reference compound. In addition experimental shifts are often found to be sensitive to environmental conditions such as solvent used, temperature, salt concentration etc. These are usually not taken into consideration in an ab initio calculation and so the comparison may only be valid if the intrinsic shift variations across a range of compounds far outweigh the environmental effects. No references to hand at the moment but I hope this helps. Best Wishes __________________________________________________________ Mark / ___ / / /| / Mark J Forster / / | / Biosym / Molecular Simulations. /__/__|/ \__O_/ 9685 Scranton Rd, /__/ | San Diego, CA 92121, USA. / | /| Tel: (619) 458 9990 / o |<-------- / | FAX: (619) 458 0136 /__ __| e-mail: mjf@biosym.com / Follower of Manchester United FC. / FA cup winners 1990, / European cup winners cup winners 1991, League cup winners 1992, / FA Premier League champions 1993, FA charity shield winners 1993/4. / FA Premier League champions AND FA cup winners 1994. /_________________________________________________________ ******************************************************************************* * DISCLAIMER: Unless indicated otherwise, everything in this note is * * personal opinion, not an official statement of Biosym / MSI * ******************************************************************************* From peon@medchem.dfh.dk Wed Nov 29 05:10:01 1995 Received: from danpost.uni-c.dk for peon@medchem.dfh.dk by www.ccl.net (8.6.10/950822.1) id FAA06963; Wed, 29 Nov 1995 05:09:57 -0500 Received: from medchem.dfh.dk (medchem.dfh.dk [130.225.177.15]) by danpost.uni-c.dk (8.6.4/8.6) with ESMTP id LAA27575; Wed, 29 Nov 1995 11:09:57 +0100 Received: from [130.225.177.59] by medchem.dfh.dk via SMTP (940816.SGI.8.6.9/940406.SGI) id LAA12044; Wed, 29 Nov 1995 11:33:52 +0100 Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Wed, 29 Nov 1995 11:10:00 +0100 To: "Moshe Olshansky" From: peon@medchem.dfh.dk (Per-Ola Norrby) Subject: Re: CCL:combining different basis sets - an addition Cc: chemistry@www.ccl.net Moshe Olshansky wrote <>: > >P.S. and now I have an additional question: > I am a mathematician, not a chemist, so let me look at the > basis sets purely mathematically. If one has a complete (and > hence necessarily infinite) basis set, he/she gets a limit > of Hartree-Fock model. Otherwise (with limited basis set) one > gets some approximation to this limit and the more complete the > basis set is the better is the approximation. Now assume one > uses a certain "standard" basis set and gets some result (from > Hartree-Fock model). And now we add ANY additional function to > this basis set. This does not make the basis set less complete > and so it should lead to at least as good (or even better) an > approximation as the original basis did (it is also possible > to get the original solution by taking that additional function > with zero coefficient for every electron). > Is there anything wrong with this statement? It of course depends on what you mean with "better". The SCF will minimize the energy, adding any new function should give an energy closer to the HF limit. However, most of the time this is not really interesting. When you want energies, you usually want relative energies, and then it's quite important that you make the same approximations, that is, calculate at a constant level of theory, so that systematic errors cancel. Also, as you said in the part of the message I deleted, adding functions in an unbalanced way will definitely affect the charge distribution, probably not making it "better" :-) Specific questions can sometimes be answered by including functions that are not atom-centered, but then you get the problem of findning a completely reproducable way of doing that for any system. Per-Ola Norrby ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ --- Bureaucracy is a challenge to be conquered with a righteous attitude, a tolerance for stupidity, and a bulldozer when necessary -- Peter's Law 15. * Per-Ola Norrby * The Royal Danish School of Pharmacy, Dept. of Med. Chem. * Universitetsparken 2, DK 2100 Copenhagen, Denmark * tel. +45-35376777-506, +45-35370850 fax +45-35372209 * Internet: peon@medchem.dfh.dk, peo@compchem.dfh.dk From owner-chemistry@ccl.net Wed Nov 29 12:10:45 1995 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.6.10/950822.1) id MAA13733; Wed, 29 Nov 1995 12:10:43 -0500 Received: from mserv.rug.ac.be for JeanLuc.Verschelde@rug.ac.be by bedrock.ccl.net (8.7.1/950822.1) id MAA20905; Wed, 29 Nov 1995 12:10:39 -0500 (EST) Received: from allserv.rug.ac.be by mserv.rug.ac.be with SMTP id AA08183 (5.67b/IDA-1.5 for ); Wed, 29 Nov 1995 18:10:33 +0100 Received: by allserv.rug.ac.be (5.x/SMI-SVR4) id AA29103; Wed, 29 Nov 1995 18:10:21 +0100 Date: Wed, 29 Nov 1995 18:10:20 +0100 (MET) From: Jean-Luc Verschelde To: OHIO SUPER Subject: solvent continuum Message-Id: Hi all, I want to extend the ECEPP/2 force field with a solvation energy term. Is there a stand-alone package that calculates the energy of solvation and that I can use with the ECEPP/2 f.f. . Thanks, Jean-Luc =================================================================================== Verschelde Jean-Luc University of Ghent Lab. of Physiological Chemistry K.L. Ledeganckstraat 35 9000 Ghent Belgium. Tel.:09/264 53 06 Fax:09/264 53 37 Email:Jeanluc.Verschelde@rug.ac.be 46q=================================================================================== From owner-chemistry@ccl.net Thu Nov 30 10:35:37 1995 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.6.10/950822.1) id KAA04073; Thu, 30 Nov 1995 10:35:36 -0500 Received: from nessie.mcc.ac.uk for darryl@om3.ch.umist.ac.uk by bedrock.ccl.net (8.7.1/950822.1) id KAA02978; Thu, 30 Nov 1995 10:35:33 -0500 (EST) Received: from om3.ch.umist.ac.uk (actually trigger.ch.umist.ac.uk) by nessie.mcc.ac.uk with SMTP (PP); Thu, 30 Nov 1995 15:35:03 +0000 Received: by om3.ch.umist.ac.uk (940406.SGI/) for chemistry%ccl.net@nessie.mcc.ac.uk id AA09214; Thu, 30 Nov 95 15:52:56 GMT Date: Thu, 30 Nov 1995 15:52:56 +0000 (GMT) From: Darryl Ellson Subject: DZP' Basis Sets. To: chemistry@ccl.net Message-Id: Dear All, Recently I have been using the DZP' basis set of Barone et al in the study of phenoxyl radicals. In the future I would like to extend this study to the histidine and tryptophanyl radicals. What I would like to know is whether anyone out there has used this basis set (also designated Chip1 by Chipman) for any systems containing Nitrogen, and whether they have access to the numerical values and the contraction coefficients for nitrogen, and would be willing to share these. Many Thanks. Darryl A. Ellson. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Darryl A. Ellson - Dept. Chemistry, UMIST, Manchester. M60 1QD Molecular Simulation & Design Laboratory Tel: 061-236-3311 x4476 Fax: 061-236-7677 E-mail: darryl@trigger.ch.umist.ac.uk ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From owner-chemistry@ccl.net Thu Nov 30 22:09:30 1995 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.6.10/950822.1) id WAA16845; Thu, 30 Nov 1995 22:03:50 -0500 Received: from blackburn.med.su.oz.au for jeremy@med.su.oz.au by bedrock.ccl.net (8.7.1/950822.1) id WAA09831; Thu, 30 Nov 1995 22:03:39 -0500 (EST) Received: (jeremy@localhost) by blackburn.med.su.oz.au (8.6.11/8.6.4) id OAA28138 for chemistry@ccl.net Fri, 1 Dec 1995 14:03:27 +1100 From: Jeremy R Greenwood Message-Id: <199512010303.OAA28138@blackburn.med.su.oz.au> Subject: Small +ve freqs in HF To: chemistry@ccl.net Date: Fri, 1 Dec 1995 14:03:26 +1100 (EST) X-Mailer: ELM [version 2.4 PL23] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Greetings all, Some simple questions for those more familiar with ab initio than I: As I understand it, the presence of a small real frequency in a Hartree-Fock calculation is regarded as evidence that on increasing basis size, the constrained structure may turn out to be a saddle point, with the mode in question becomming imaginary. My question is: How small is small? I am performing calculations on semi-aromatic heterocycles, and at HF|6-31g* in Cs symmetry, I find a frequency of 8 /cm. Others around 30-50 /cm. The ring is somewhat prone to puckering, and indeed some similar calculations have produced C1 structures. My other question is: Does inclusion of electron correlation (e.g. MP2) with analytic second derivatives tend to produce similar results in terms of symmetry breaking as increasing basis set? (I understand that answers to these questions may depend very much on the nature of the systems being studied.) Jeremy -- Jeremy Greenwood Department of Pharmacology University of Sydney From parcom.ernet.in!gadre@parcom.ernet.in Thu Nov 30 23:09:31 1995 Received: from sangam.ncst.ernet.in for parcom.ernet.in!gadre@parcom.ernet.in by www.ccl.net (8.6.10/950822.1) id WAA17260; Thu, 30 Nov 1995 22:54:42 -0500 Received: from parcom.UUCP (uucp@localhost) by sangam.ncst.ernet.in (8.6.12/8.6.6) with UUCP id JAA03295 for CHEMISTRY@www.ccl.net; Fri, 1 Dec 1995 09:26:13 +0530 Received: from parcom.UUCP by iucaa (4.1/SMI-4.1) id AA14913; Fri, 1 Dec 95 09:25:11+050 Received: from parcom by parcom.parcom.ernet.in (4.1/SMI-4.1) id AA17688; Fri Dec 1 09:00:40 1995 (GMT + 0530) Date: Fri Dec 1 09:00:40 1995 (GMT + 0530) From: gadre@parcom.ernet.in Message-Id: <9512010330.AA17688@parcom.parcom.ernet.in> To: CHEMISTRY@www.ccl.net Subject: Buckingham-Fowler and Legon-Millen Models Dear Colleagues : Could you send me a list of successes/failures of Buckingham-Fowler as well as Legon-Millen models for studying weak intermolecular complexes? One success, for instance is the reasonable geometry for the HCHO-HF complex using the former. Needless to say that I am more interested in failures! Thanks a lot. .........................................Shridhar R. Gadre November 30, 1995.