From NEDWED@ptc.tu-graz.ac.at Mon Mar 7 05:06:18 1994 Received: from edvz.tu-graz.ac.at for NEDWED@ptc.tu-graz.ac.at by www.ccl.net (8.6.4/930601.1506) id EAA01491; Mon, 7 Mar 1994 04:59:21 -0500 Received: by edvz.tu-graz.ac.at (5.57/Ultrix3.0-C) id AA15499; Mon, 7 Mar 94 10:59:36 +0100 Received: from PTC/SMTPQueue by ptc.tu-graz.ac.at (Mercury 1.11); Mon, 7 Mar 94 10:57:46 +0100 Received: from Mailqueue by PTC (Mercury 1.11); Mon, 7 Mar 94 10:57:15 +0100 From: "Dipl.-Ing. Karl NEDWED" Organization: TU Graz To: CHEMISTRY@ccl.net Date: Mon, 7 Mar 1994 10:57:08 +0100 X-Pmuue: SYMWORLD.DOC X-Finfo: DOS,"SYMWORLD.DOC",,,,Text Subject: New software for automatic point group determinations Priority: normal X-Mailer: PMail v3.0 (R1a) Message-Id: <2A27A2245DE@ptc.tu-graz.ac.at> * This message contains the file 'SYMWORLD.DOC', which has been * uuencoded. If you are using Pegasus Mail, then you can use * the browser's eXtract function to lift the original contents * out to a file, otherwise you will have to extract the message * and uudecode it manually. begin 660 SYMWORLD.DOC M1&5A2P@:2YE M+B!W:71H(&$@8V]M<'5T97(N($$@;G5M8F5R(&]F(&UE=&AO9',@#0IH879E M(&)E96X@9&5V96QO<&5D+"!B=70@=&AE>2!A;&P@;&%C:R!E:71H97(@87!P M;&EC86)I;&ET>2!T;R!A(&-O;7!U=&5R(&]R(`T*&ES=&EN9R!P;VEN="!G2!I;B!A M(')E87-O;F%B;&4@=&EM92P-"BH@;&5T7-T96US('5N9&5R($U3(%=I;F1O=W,H4BDN M(`T*5&AE(&UA:6X@9F5A='5R97,@87)E.@T**B!);G!U="!O9B!M;VQE8W5L M87(@9&%T82!V:6$@86)S;VQU=&4@*$-A2!R97-T2!P87)A;65T97(@5"P@=VAI8V@@8V%N(&)E(&-H;W-E;B!F2!B92!I;B!O M6UM971R>2X@1F]R(&5X86UP;&4L(&EF(&$@#0H@('!A M2!T:&4@86)S;VQU=&4@=F%L=64@;V8@5"X-"BH@ M5FES=6%L:7IA=&EO;B!O9B!M;VQE8W5L97,@:6X@82!T:')E92UD:6UE;G-I M;VYA;"P@<&5RF%T:6]N(&]F(&UO;&5C M=6QE2!P;VEN="!G7-I8VES=',@86YD(`T*8W)YBYA8RYA=`T*#0IOBYA8RYA=`T**BHJ;&]G:6XZ(&%N M;VYY;6]U3H@<'5B7&US9&]S7'-Y;6%P<',-"@T*5&AE(&9U;&P@=F5R M2!A(&QO="!O9B!T:6UE+6-O;G-U;6EN9R`-"F-O;7!U=&%T:6]N; Mon, 7 Mar 1994 10:43:59 GMT+1 X400-Received: by mta iris-dcp in /PRMD=iris/ADMD=mensatex/C=es/; Relayed; Mon, 7 Mar 1994 10:41:45 UTC+0100 X400-Received: by /PRMD=iris/ADMD=mensatex/C=es/; Relayed; Mon, 7 Mar 1994 10:41:31 UTC+0200 Date: Mon, 7 Mar 1994 10:41:31 UTC+0200 From: Juan Frau Subject: Questions about GAMESS To: chemistry@ccl.net Message-id: <98*/S=dqujfm0/OU=PS/O=uib/PRMD=iris/ADMD=mensatex/C=es/@MHS> Content-identifier: 98 Content-transfer-encoding: 7BIT Conversion: Prohibited X400-Content-type: P2-1984 (2) X400-MTS-identifier: [/PRMD=iris/ADMD=mensatex/C=es/;940307104131] X400-Originator: dqujfm0@PS.uib.es X400-Recipients: chemistry@ccl.net Dear Netters, I have a small experience with GAMESS, and today I have a problems with it. I want to do a reaction coordinate from a structure completely optimized. I have so internas so cartesianes coordinates. And I tried to keep constant a bond length, using the key-word IFREEZ=N, n is the number of the intern coordinate definited in IZMAT. When I run this file, I get a structure very strange. And the bond length n has changed. Why? Had I kept it constant or not? How can I do this calculation? If you have the solution to the problem, please tell me it. Thanks in advance.Juan ************************************************** Juan Frau. Universitat Illes Balears. Dep Quimica Palma de Mallorca 07071. Baleares. Spain Email:dqujfm0@ps.uib.es fax: 34 71 17-34-26 ************************************************** From UNC4B2@plumbum.chemie.uni-bonn.de Mon Mar 7 06:07:15 1994 Received: from IBM.rhrz.uni-bonn.de for UNC4B2@plumbum.chemie.uni-bonn.de by www.ccl.net (8.6.4/930601.1506) id FAA01674; Mon, 7 Mar 1994 05:16:43 -0500 Received: from plumbum.chemie.uni-bonn.de by IBM.rhrz.uni-bonn.de (IBM VM SMTP V2R2) with TCP; Mon, 07 Mar 94 11:16:03 MEZ Received: from SNCHEMIE1/MERCURY by plumbum.chemie.uni-bonn.de (Mercury 1.11); Mon, 7 Mar 94 11:13:02 EST Received: from MERCURY by SNCHEMIE1 (Mercury 1.11); Mon, 7 Mar 94 11:12:23 EST To: CHEMISTRY@ccl.net From: "Christoph Steinbeck " Organization: Dep. of Chemistry, Bonn Date: Mon, 7 Mar 1994 11:12:19 EST Subject: structure from connectivity matrix Reply-to: steinbeck@uni-bonn.de Priority: normal X-mailer: WinPMail v1.0 (R2) Message-ID: <1493CD171C5@plumbum.chemie.uni-bonn.de> Hello all, I'm still having the problem of drawing a 2D-Strucuture from a connnectivity-matrix. Some answers concerning my last request in this list pointed to an article of Bley, Brandt, Dengler, Frank and Ugi in J.Chem. Research (M), 1991, 1273-1281. This is very interesting and I have the text in printed form but need it in computer-readable format as ascii text. Unfortunately, the munich group does not respond to my letters. Does anybody have this text in ascii-format? Can anybody give me an E-Mail-Adress of a member of Ugi's group? Thanks for any help, Chris -- Christoph Steinbeck (STEINBECK@UNI-BONN.DE) Abt. Prof. Breitmaier, Dep. of Chemistry, Univ. Bonn, Gerhard-Domagk-Str. 1, 53121 Bonn 1, GERMANY Tel.: (49) 228 735669, Fax: (49) 228 735683 *** If life gives you a lemon - make lemonade! *** From NEDWED@ptc.tu-graz.ac.at Mon Mar 7 06:07:55 1994 Received: from edvz.tu-graz.ac.at for NEDWED@ptc.tu-graz.ac.at by www.ccl.net (8.6.4/930601.1506) id FAA01790; Mon, 7 Mar 1994 05:48:50 -0500 Received: by edvz.tu-graz.ac.at (5.57/Ultrix3.0-C) id AA15713; Mon, 7 Mar 94 11:49:04 +0100 Received: from PTC/SMTPQueue by ptc.tu-graz.ac.at (Mercury 1.11); Mon, 7 Mar 94 11:47:14 +0100 Received: from Mailqueue by PTC (Mercury 1.11); Mon, 7 Mar 94 11:46:52 +0100 From: "Dipl.-Ing. Karl NEDWED" Organization: TU Graz To: CHEMISTRY@ccl.net Date: Mon, 7 Mar 1994 11:46:47 +0100 Subject: Correction to: New software for automatic point group deter> Priority: normal X-Mailer: PMail v3.0 (R1a) Message-Id: <2A34DD37AA5@ptc.tu-graz.ac.at> Dear netters, sorry for the garbage in the first exploded message you have just received. Within the last few years there have piled up requests how to determine point groups of molecules automatically, i.e. with a computer. A number of methods have been developed, but they all lack either applicability to a computer or suitability to determine all existing point groups. A computer program is needed that * determines the point group of molecules automatically in a reasonable time, * lets point group determinations pe performed, even of distorted molecules(!), * lets multiple point group determinations of the same molecule be performed, each one with a different allowance of distortion. We have been working on this problem for a year now and are proud to present a software that will do ALL THIS for you and and a lot more. The computer program is called SYMAPPS for Windows and runs on IBM PC or compatible systems under MS Windows(R). The main features are: * Input of molecular data via absolute (Cartesian) coordinates. * Input of molecular data via internal (Z-matrix) coordinates. * Automatic point group determinations of any molecule. Neither the size of the molecule nor the detected point group is subject to any restrictions (apart from computer memory). The extent of distortion can be gauged by a so-called uncertainty parameter T, which can be chosen from 0 to about 0.7. The greater T, the greater the distortion of the molecule may be in order to still find an idealized point group of high symmetry. For example, if a particular compound shows a Jahn-Teller-Effect, with a small value of T the point group D4h will be found, while for larger values of T the group Oh will occur. It is the user's task to decide, if in his computations the distortion is too large to use Oh or not. In any case, the extent of distortion can be gauged by the absolute value of T. * Visualization of molecules in a three-dimensional, perspective outline mode on screen. Only bonds and atom identifiers are displayed in this mode. Real time rotating and resizing is possible. * Visualization of molecules in the three-dimensional perspective spacefill mode on screen, where atoms assume spherical shapes. * Display of the character tables of arbitrary point groups (not restricted to the 32 crystallographic ones). * Reduction of reducible representations into their irreducible components. SYMAPPS for Windows will be of great use to chemists physicists and crystallographers, involved in both research and teaching. For a demo version, please contact ***Karl NEDWED ***Institute for Physical and Theoretical Chemistry ***Graz Institute of Technology ***A-8010 Graz ***Austria ***E-mail address: nedwed@ptc.tu-graz.ac.at or simply ftp it from ***server: ftp.tu-graz.ac.at ***login: anonymous ***password: your E-mail address ***directory: pub\msdos\symapps The full version will be available soon. A single user edition will be US$100 (excl. 20% VAT and delivery), for site licenses please contact us. We hope that SYMAPPS for Windows will simplify a lot of time-consuming computations and determinations in laboratories. From jkl@ccl.net Mon Mar 7 11:07:21 1994 Received: from krakow.ccl.net for jkl@ccl.net by www.ccl.net (8.6.4/930601.1506) id KAA03769; Mon, 7 Mar 1994 10:50:41 -0500 From: Jan Labanowski Received: from localhost for jkl@ccl.net by krakow.ccl.net (8.6.4/920428.1525) id KAA06316; Mon, 7 Mar 1994 10:50:40 -0500 Date: Mon, 7 Mar 1994 10:50:40 -0500 Message-Id: <199403071550.KAA06316@krakow.ccl.net> To: chemistry@ccl.net Subject: Molecular Modeling software list available Cc: jkl@ccl.net Dear Chemists, Thanks to Didier Vanderveken (vdvk@netcom.com) we have an updated version of list of Molecular Graphics Packages. The easiest way to view it is to use gopher: gopher www.ccl.net Choose Other OSC Gophers, then Chemistry, then documents, and then molecular_graphics_packages. Since the file conforms to the UNIX mailbox format, you can view it by Subjects. You can also retrieve the whole file via ftp: ftp www.ccl.net Name: anonymous Password: Your_True_E-mail_Address ftp> cd pub/chemistry/documents ftp> get molecular_graphics_packages ftp> quit For people without ftp access, you can still get it via e-mail. If you want to preserve the mailbox format, you need to uuencode it (i.e., use the command: get molecular_graphics_packages | uuencode) since the email will change every From ???@??? line to >From ???@???. You can also use the editor to clean this up. So, if you want to get this via e-mail send the message: select chemistry size 60kb cd documents ls get molecular_graphics_packages quit Thanks Didier for your very needed contribution. -- Dr. Jan K. Labanowski, Senior Research/Supercomputer Scientist/Specialist, etc. Ohio Supercomputer Center, 1224 Kinnear Rd, Columbus, OH 43212-1163 ph:(614)-292-9279, FAX:(614)-292-7168, E-mail: jkl@ccl.net JKL@OHSTPY.BITNET From kkemete1@gwdg.de Mon Mar 7 14:06:16 1994 Received: from gwdu17.gwdg.de for kkemete1@gwdg.de by www.ccl.net (8.6.4/930601.1506) id NAA05897; Mon, 7 Mar 1994 13:11:50 -0500 Received: from gwdu03.gwdg.de by gwdu17.gwdg.de with SMTP (PP); Mon, 7 Mar 1994 19:15:31 +0100 Received: by gwdu03.gwdg.de (5.57/ultrix-03-gwdg) id AA10893; Mon, 7 Mar 94 19:11:20 +0100 From: kkemete1@gwdg.de (Karsten Kemeter) Message-Id: <9403071811.AA10893@gwdu03.gwdg.de> Subject: co2-potential-parameters To: chemistry@ccl.net Date: Mon, 7 Mar 1994 19:11:19 +0100 (MET) Content-Type: text Content-Length: 711 Dear Netters, for some MD_simulations we would like to have potentials for CO2. I just know a work of Singer, Singer, Taylor from 1977 (Mol.Phys. 33), but it is not that good in reproducing thermodynamik properties. Does anybody know a good database for that or even a reference? Many thanks in advance Karsten Kemeter ::::::::::::::::::::::::::::::::::::::::::::::::::::::: | Max-Planck-Institut fuer Biophysikalische Chemie | | Abteilung Laserphysik | | | | Am Fassberg | | 37077 Goettingen | | | | Tel.: xx49/551/201-339 | | FAX.: xx49/551/201-341 | | e-mail: kkemete1@gwdg.de | ::::::::::::::::::::::::::::::::::::::::::::::::::::::: From leboeuf@CHIMCN.UMontreal.CA Mon Mar 7 16:06:28 1994 Received: from condor.CC.UMontreal.CA for leboeuf@CHIMCN.UMontreal.CA by www.ccl.net (8.6.4/930601.1506) id PAA07665; Mon, 7 Mar 1994 15:21:54 -0500 Received: from chims1.CHIMCN.UMontreal.CA by condor.CC.UMontreal.CA with SMTP id AA28833 (5.65c/IDA-1.4.4 for chemistry@ccl.net); Mon, 7 Mar 1994 15:19:00 -0500 Received: by chims1.CHIMCN.UMontreal.CA (930416.SGI/5.17) id AA24320; Mon, 7 Mar 94 15:18:28 -0500 From: leboeuf@CHIMCN.UMontreal.CA (Leboeuf Martin) Message-Id: <9403072018.AA24320@chims1.CHIMCN.UMontreal.CA> Subject: Summary of optimal distribution of charges on sphere To: chemistry@ccl.net Date: Mon, 7 Mar 1994 15:18:28 -0500 (EST) Cc: leboeuf@CERCA.UMontreal.CA Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 8377 Hi Netters, Here is the summary of our request about the distribution of charges on a sphere. If I have forgotten something, please forgive me and also tell me, so I can make the appropriate correction. And thanx to all of you who responded. Original posting: ---------------- > Dear CCLers, > > A computational fluid dynamics friend has asked if we chemists know > anything about the distribution of points (charges) on a sphere. > (He is interested in bubbles) > I remember seeing some papers on this question but can't place them. > There is some work in theoretical inorganic chemistry and some > demonstrations of the optimal configurations for quite high N (the > number of points). > > Any clues? Please reply to leboeuf@cerca.umontreal.ca and Martin > Leboeuf or I will summarize to the net, if it seems appropriate. > > Dennis Salahub Answers: ------- Minimum - Energy Configurations For Charges on the Surface of A Sphere S. Webb Chem. Phys. Lett. v. 129, #3 pp.310-314, 1986 Searching potential energy surfaces by simulated annealing L. T. Willie Nature v. 324, Nov. 6., pp.46-48, 1986 gus mercier mercie@cumc.cornell.edu ------------------------------------------------------------------------ GILLESPIE R.J. CAN. J. CHEM. 1960 VOL 38 PAGE 818 ELECTRON CORRELATION AND MOLECULAR SHAPE. ARRANGEMENTS OF ELECTRONPAIRS AND BONDS ON THE SURFACE OF A SPHERE. =================== J.N. RIDLEY MATHEMATICAL BIOSCIENCES 1986 VOL 79 PAGE 1 IDEAL PHYLLOTAXIS ON GENERAL SURFACES OF REVOLUTION. IDEAL PLACEMENT OF ANY NUMBER OF POINTS ON THE SPHERE. =================== J.N. RIDLEY MATHEMATICAL BIOSCIENCES 1982 VOL 58 PAGE 129 PACKING EFFICIENCY IN SUNFLOWER SEEDS. PLACEMENT OF ANY NUMBER OF POINTS ON A SPHERE. =================== SCHUTTE K. AND VAN DER WAERDEN B.L. MATH. ANN. 1951 VOL 123 PAGE 96 THE PLACEMENT OF POINTS EQUIDISTANT ON THE SPHERE. MATHEMATICAL PROOFS. Dr Charles Marais ------------------------------------------------------------------------ I read a paper (I think in J. Mol. Graphics) that the optimal spacing of points on a sphere arises from the mapping of the vertices of an isoahedron. The paper was by P. Chau (and possibly P. Dean). Chau wrote a FORTRAN program to map these points, and by interpolating between the vertices can give as many points as desired. You can contact Chau by email for further information and his program at pc104@ddg.phar.cam.ac.uk keith trollope. ------------------------------------------------------------------------ You could look at our recent paper "Energies and spacings of point charges on a sphere" L Glasser and AG Every J Phys A:25 (1992) 2473-82, which also contains a brief review of the field. Yours sincerely, Leslie Glasser ------------------------------------------------------------------------ In response to your CCL message, I remembered that a couple of years ago someone asked a similar question, and then summarized for the net----the questioner was lim@rani.chem.yale.edu; you might contact him for the summary he sent out then. I only have it on paper at this point---if you have difficulties in getting i via e-mail, I'll be glad to fax you a copy. With greetings, Bob Carter This inquiery was about the random distribution of points on a sphere, which is a bit different then what we are looking for. And this is an FAQ in comp.graphics. Anyways, IF you REALLY whish to also have a copy, contact me, not Bob Carter (-ML) ------------------------------------------------------------------------ J.B. Weinrach, K.L. Carter, D.W. Bennett, and H.K. McDowell, J. Chem. Ed. 67, 995 (1990) I believe it discusses the structures shown to minimize the repulsion between a set of particles on a sphere interacting via a d^(-1) potential, where d is the interparticle distance. Mark Stave ------------------------------------------------------------------------ The work published in Nature 324, 46-48 (1986) considers the problem of finding the minimum energy configuration of equal charges confined to a sphere. It also contains a number of references to previous numerical and analytical work in the same or very similar problems. Max Vasquez ------------------------------------------------------------------------ I think the placement of similarly charged points optimally on a sphere is the same as the rotational grid optimization problem. I published a paper on this in Canadian J. Chem. 51, 312 (1973). It is also possible to treat this subject using quaternions. -Don Williams ------------------------------------------------------------------------ I know of 2 answers to your question: i) J. Chem. Ed. v67, 995, (1990) ii) J. Mol. Graph. v5, 97, (1987) Richard Bone ------------------------------------------------------------------------ It's not perfectly clear what you mean by "optimal configuration", but I recall that there are points quite evenly distributed around the sphere in the Lebedev and Konyaev quadrature schemes. (These are the quadratures on the surface of a sphere that Axel Becke used in the NUMOL integration method.) However, I don't recall that there were actually any theorems given with regard to the "evenness" of the distributions, so these may not meet your colleague's needs. Here are the references anyway: author="A. D. Becke", title="A fully numerical integration scheme for polyatomic molecules", journal=jcp, year=1988, volume=88, number=4, pages="2547--2553" author="V. I. Lebedev", title="Values of the nodes and weights of ninth to seventeenth order Gauss-Markov quadrature formulae invariant under the octahedron groups with inversion", journal="Zh. Vychisl. Mat. Mat. Fiz.", year=1975, volume=15, number=1, pages="48--54" author="V. I. Lebedev", title="Quadratures on a sphere", journal="Zh. Vychisl. Mat. Mat. Fiz.", year=1976, volume=16, number=2, pages="293--306" author="V. I. Lebedev", title="Spherical quadrature formulas exact to orders 25--29", journal="Sibirsk. Mat. Zh.", year=1977, volume=18, number=1, pages="132--142" author="S. I. Konyaev", title="?", journal="Mat. Zametki", year=1979, volume=25, number=?, pages="629" Ross M. Dickson ------------------------------------------------------------------------ I am not sure whether this is relevant answer on your inquiry regarding optimal configuration of point charges on a sphere. Some time ago we developed a procedure which allows to generate sets of point charges on the sphere around each atom reproducing exactly Cumulative Atomic Multipole Moments (CAMM), which are calculated directly >from any quantum chemical wavefunction (SCF, CI, MRD-CI, MBPT, etc.). Perhaps it may be interesting for you that very recently we adapted this procedure within the framework of Density Functional Theory. This allows to store detailed information about charge distribution for very large molecules in a very compact form suitable for databases. In the fact such databases have been already collected for aminoacids and nucleic acid bases. Such Point Charges are located on a sphere around each atom and reproduce exactly not only molecular multipole moments, but also atomic multipole moments. More details could be found in Theor.Chim.Acta, 85,209-216 (1993) or Int.J.Quantum Chem, Quantum Biology Symp. 14,111 (1987) W.A. Sokalski ------------------------------------------------------------------------ I'm aware of a paper describing the gnomonic projection of atomic charge points from a molecule onto a spherical surface that may be of interest to you... PL Chau and PM Dean, J. Mol. Graphics, Vol 5, (1987), pp 97-100. Hope this is what you were looking for. Gregory L. Durst ------------------------------------------------------------------------ Again, thank you all, Martin Martin Leboeuf CERCA - CEntre de Recherche en Calcul Applique et Departement de Chimie, Universite de Montreal Montreal, Quebec e-mail: leboeuf@CERCA.UMontreal.CA From cqsimpson@halnet.com Mon Mar 7 17:39:30 1994 Received: from interlock.halnet.com for cqsimpson@halnet.com by www.ccl.net (8.6.4/930601.1506) id RAA09096; Mon, 7 Mar 1994 17:08:24 -0500 Received: by interlock.halnet.com id AA08158 (InterLock SMTP Gateway 1.1 for chemistry@ccl.net); Mon, 7 Mar 1994 16:08:16 -0600 Received: by interlock.halnet.com (Internal Mail Agent-1); Mon, 7 Mar 1994 16:08:16 -0600 Date: Mon, 7 Mar 1994 16:07:52 -0600 From: cqsimpson@halnet.com (Charlie Simpson) Message-Id: <9403072207.AA22065@cre2> To: chemistry@ccl.net Subject: GRID Program Howdy Netters: Does anyone know if the GRID program is available, and if so, who I can contact to get it? Many thanks in advance. Cordially, ================================================================================ Charlie Simpson Ph.D. cqsimpson@halnet.com Halliburton Energy Services P.O. Box 1431 Phone 405/251-4564 Duncan, OK 73536-0438 Fax 405/251-3218 We have staked the whole future of the American civilization, not upon the power of government, far from it. We have staked the future...upon the capacity of each and all of us to govern ourselves, to control ourselves, to sustain ourselves, according to the Ten Commandments of God. James Madison ================================================================================ From wallyr@netcom.com Mon Mar 7 18:39:30 1994 Received: from netcom9.netcom.com for wallyr@netcom.com by www.ccl.net (8.6.4/930601.1506) id SAA09770; Mon, 7 Mar 1994 18:18:10 -0500 Received: from localhost by netcom9.netcom.com (8.6.4/SMI-4.1/Netcom) id PAA27724; Mon, 7 Mar 1994 15:19:03 -0800 From: wallyr@netcom.com (Walter E. Reiher III) Message-Id: <199403072319.PAA27724@netcom9.netcom.com> Subject: ESP charges fit to dipole in MOPAC93 To: CHEMISTRY@ccl.net Date: Mon, 7 Mar 1994 15:19:02 -0800 (PST) X-Mailer: ELM [version 2.4 PL23] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1754 I'm trying out MOPAC 93 and have encountered the following unexpected result: when fitting atom-centered point charges using the 'ESP' keyword, I find that the charges obtained with the 'DIPOLE' keyword (which is supposed to 'fit the ESP to the calculated dipole') give charges which physically unreasonable and have a *worse* fit to the calculated dipole. My test case is water, experimental geometry, and I made two runs including the following keywords: AM1 AIGIN MULLIK + ESP CONNOLLY NSURF=4 SCALE=1.4 SCINCR=0.2 SYMAVG MOPAC 93 gave me ESP-fit charges of 0.2279 and -0.4557, giving a 'dipole computed from point charges' of 1.2828. The computed dipole moment was good, 1.854, so I thought I would try biasing the fit to the calculated dipole. In my second run, I added the keyword 'DIPOLE' to the above set. MOPAC 93 gave me H's more charged than the O and charges of opposite sign on the H's! ELECTROSTATIC POTENTIAL CHARGES DIPOLE CONSTRAINTS WILL BE USED ATOM NO. TYPE CHARGE 1 O -0.0013 2 H -0.0480 3 H 0.0173 Besides this, the dipole moment is too small. It can't be just a scaling error, since the H's are so different. I scanned the CCL archives and couldn't find anything on this. Anyone have an idea? Thanks. Wally ======================================================================== Walter E. Reiher III, Ph.D. WallyR@netcom.com Consultant in Computational Chemistry voice 408-720-0240 P.O. Box 61056 fax 408-720-0378 Sunnyvale, CA 94088 24-hr voice mail 408-534-1171 From raman@bioc01.uthscsa.edu Mon Mar 7 20:39:31 1994 Received: from thorin.uthscsa.edu for raman@bioc01.uthscsa.edu by www.ccl.net (8.6.4/930601.1506) id TAA10480; Mon, 7 Mar 1994 19:48:28 -0500 Received: from bioc01.uthscsa.edu by thorin.uthscsa.edu with SMTP; Mon, 7 Mar 1994 18:48:14 -0600 (CST) Received: by bioc01.uthscsa.edu (4.1/SMI-4.1) id AA19453; Mon, 7 Mar 94 18:47:53 CST From: raman@bioc01.uthscsa.edu (C.S.RAMAN) Message-Id: <9403080047.AA19453@bioc01.uthscsa.edu> Subject: Re: CCL:GRID Program To: cqsimpson@halnet.com (Charlie Simpson) Date: Mon, 7 Mar 1994 18:47:52 -0600 (CST) Cc: chemistry@ccl.net In-Reply-To: <9403072207.AA22065@cre2> from "Charlie Simpson" at Mar 7, 94 04:07:52 pm X-Mailer: ELM [version 2.4 PL3] Content-Type: text Content-Length: 1237 > Does anyone know if the GRID program is available, and if so, who I can > contact to get it? Many thanks in advance. Dr. Peter Goodford can be reached at: peter@biop.ox.ac.uk The program GRID is distributed by: Molecular Discovery Ltd. West Way House Elms Parade Oxford OX2 9LL U.K. Contact person: Mrs. Henrietta Elton Phone: +44-993-830385 Fax: +44-993-830966 Alternatively you could contact Dr. Peter Goodford (author of the program) at: peter@biop.ox.ac.uk Cheers -raman -- C.S.Raman raman@bioc01.uthscsa.edu - Internet UNIX Programming & Administration 70412.2354@compuserve.com - CIS SPARC & SGI Systems raman@hermes.chpc.utexas.edu - CHPC Department of Biochemistry c.raman@launchpad.unc.edu UTHSCSA 7703 Floyd Curl Dr. (210) 567-6623 [Tel] San Antonio, TX 78284-7760 (210) 567-6595 [Fax] ****************************************************************************** If a man's wit be wandering, let him study the Mathematics -Francis Bacon ******************************************************************************