From ilya@lisboa.ks.uiuc.edu Mon Oct 4 18:45:47 1993 From: Ilya Logunov Message-Id: <9310050445.AA19663@lisboa.ks.uiuc.edu> Date: Mon, 4 Oct 93 23:45:47 -0500 To: chemistry@ccl.net Subject: Books on semi-emperical methods Could somebody recommend to me a good, up-to-date book on semi-empirical methods in quantum chemistry? All responses will be very much appreciated, summarized, and posted. ********************************************************* Ilya Logunov University of Illinois at U-C ilya@lisboa.ks.uiuc.edu ********************************************************* From mckelvey@Kodak.COM Tue Oct 5 05:02:21 1993 Date: Tue, 5 Oct 93 09:02:21 -0400 Message-Id: <9310051302.AA20028@Kodak.COM> From: mckelvey@Kodak.COM To: osc@Kodak.COM Subject: Semiempirical theory text Someone ought to encourage Karl Jug to collect his works, which are masterful review articles published in TCA, into a book. It would probably be a definitive volume in the area. John McKelvey From jaeric@mtcamm.monsanto.com Tue Oct 5 02:55:03 1993 From: Jon A. Erickson Message-Id: <9310051255.AA00858@mtcamm.monsanto.com> Subject: Re: Books on semi-emperical methods To: chemistry@ccl.net (OSU Comp. Chem. List) Date: Tue, 5 Oct 93 7:55:03 CDT > Could somebody recommend to me a good, up-to-date book on > semi-empirical methods in quantum chemistry? All responses will be > very much appreciated, summarized, and posted. > > > ********************************************************* > Ilya Logunov > University of Illinois at U-C > ilya@lisboa.ks.uiuc.edu > ********************************************************* Try the two chapters in "Reviews in Comp. Chem." ed. Lipkowitz and Boyd, one by Jimmy Stewart (Vol 1) and the other by Micheal Zerner (Vol 2). Tim Clark's "Handbook of Comp. Chem." is also a good place to start. -- ################################################################ # Jon Erickson e-mail: jaeric@mtcamm.monsanto.com # # Monsanto Company, U3E phone: (314) 694-1511 # # 800 N. Lindbergh Blvd. FAX: (314) 694-1080 # # St. Louis MO, 63167 # # # # What is a magician but a practising theorist? # # -- Obi-Wan Kenobi # ################################################################ From ravishan@tulip.wcc.wesleyan.edu Tue Oct 5 04:44:02 1993 Date: Tue, 5 Oct 1993 08:44:02 -0400 Message-Id: <9310051244.AA15843@tulip.wcc.wesleyan.edu> From: G. Ravishanker To: mikes@bioch.ox.ac.uk Subject: Re: Cluster Analysis Mike That is the simplest way to cluster them. And this procedure, called 2-D RMS Map by us, turns out to be a very useful tool to cluster and monitor structural grouping in an MD. We construct a symmetrix matrix RMS(i,j) where i and j are indices of the average structures over portions of trajectory. This matrix is laid out on a 2-D grid using a continuous spectrum of color to code the value of RMS at the grid (i,j). As is obvious, the diagonals are zero and 1A blocks are usually around the diagonal and various squares or rectangles develop around the diagonal showing the persistence of a given structural group. We can also block them using the same color for say rmsd of 0-1, another color for 1-2 etc. Off diagonal blocks indicate revisitation of structural groups along the trajectory. We have succesfully extended this to even compare trajectories of similar systems to capture the common structural groups visited in various trajectories. There is also facility to calculate the rmsd on only a subset of atoms (say only the sugar atoms in a DNA) which might give the "substate" picture relevent to only those that are selected. This and another 50 or so applications are collectively known as "MD Toolchest" developed here at Wesleyan. A small subset of the program set is already being distributed and the next considerably expanded version of it is getting ready for distribution in November. If any of you wish to know more about it, please let me know and I will personally correspond with you. Thank you. Ravi **************************************************************************** * Ganesan Ravishanker Ph: (203) 344-8544 Ext. 3110 * * Coordinator of Scientific Computing, Fax:(203) 344-7960 * * Adjunct Associate Professor(Dept. of Chem.) * * Wesleyan University e-mail:ravishan@swan.wesleyan.edu * * Middletown, CT 06457. * **************************************************************************** From jaeric@mtcamm.monsanto.com Tue Oct 5 03:07:12 1993 From: Jon A. Erickson Message-Id: <9310051307.AA00904@mtcamm.monsanto.com> Subject: Re: Books on semi-emperical methods To: chemistry@ccl.net (OSU Comp. Chem. List) Date: Tue, 5 Oct 93 8:07:12 CDT > Could somebody recommend to me a good, up-to-date book on > semi-empirical methods in quantum chemistry? All responses will be > very much appreciated, summarized, and posted. > > ********************************************************* > Ilya Logunov > University of Illinois at U-C > ilya@lisboa.ks.uiuc.edu > ********************************************************* > Try the two chapters in "Reviews in Comp. Chem.," ed. Lipkowitz and Boyd, one by Jimmy Stewart (vol 1) and the other by Michael Zerner (vol 2). Tim Clark's "Handbook of Comp. Chem." is also a good place to start. -- ################################################################ # Jon Erickson e-mail: jaeric@mtcamm.monsanto.com # # Monsanto Company, U3E phone: (314) 694-1511 # # 800 N. Lindbergh Blvd. FAX: (314) 694-1080 # # St. Louis MO, 63167 # # # # What is a magician but a practising theorist? # # -- Obi-Wan Kenobi # ################################################################ From rqfis5@onyar.udg.es Tue Oct 5 12:35:44 1993 Date: Tue, 05 Oct 1993 16:35:44 EDT From: rqfis5@onyar.udg.es To: chemistry@ccl.net Message-Id: <00973926.2374B2A0.9070@onyar.udg.es> Subject: model potentials in cadpac 5.0 Dear netters, does someone know whether model potentials are available in CADPAC v5.0? If they are, how are they specified for a given atom? Miquel Duran, Institute of Computational Chemistry University of Girona rqfis5@onyar.udg.es From EDGECOMK@QUCDN.QUEENSU.CA Tue Oct 5 08:37:00 1993 Message-Id: <199310051644.AA26582@oscsunb.ccl.net> Date: Tue, 5 Oct 1993 12:37 EDT From: EDGECOMK@QUCDN.QueensU.CA To: chemistry@ccl.net Subject: DFT This is getting interesting... Many of my colleagues insist that DFT is essentially basis set free. However, they do need a guess to start off and many codes 'need' basis sets. Newer numerical codes still need something to get them started. Has this guess part really the same level of effect as the basis set if HF calcns? Note that there are numerical HF codes as well. Then the choice is your grid size ... but of course then you are no longer variational either. Ken Edgecombe Dept. of Chem Queen's University From MROZEK@Trurl.ch.uj.edu.pl Tue Oct 5 17:53:31 1993 From: Organization: Faculty of Chemistry, UJ To: Chemistry@ccl.net Date: Tue, 5 Oct 1993 17:49:04 MET+2 Subject: Re: MOPAC6 FOR PC? Message-Id: We are using an OS/2 PC version of MOPAC 6.0 on our machines. We did not try to activate the ESP part. The graphical presentation of the computed system (ball and stick model) is now in the works. I mean showing the currently computed geometry on request. The I/O part of the code has been extensively modified. Janusz Mrozek ==================================================== Janusz Mrozek, Department of Theoretical Chemistry & Department of Computational Methods in Chemistry Faculty of Chemistry, Jagiellonian University 3 R. Ingardena St. 30-060 Cracow, Poland ==================================================== From dickson@zinc.chem.ucalgary.ca Tue Oct 5 04:50:30 1993 Date: Tue, 5 Oct 1993 10:50:30 -0600 From: dickson@zinc.chem.ucalgary.ca Message-Id: <9310051650.AA20716@zinc.chem.ucalgary.ca> To: chemistry@ccl.net, ole.swang@kjemi.uio.no Subject: DFT and breaking bonds For an early discussion of DFT and a multi-configurational system (ozone), see Salahub, Lamson and Messmer, Chem. Phys. Lett. 85(4), 430 (1982). Briefly, Hartree-Fock predicts the wrong ordering of states for ozone, while simple DFT gets them right. The authors suggest a qualitative explanation for this behaviour, touching lightly on the matter of DFT orbital energies (raised by Jing Kong and Gustavo Mercier yesterday). I shan't mutilate their arguments by trying to reproduce them here :-) While the last eleven years of scholarship have undoubtedly surpassed this paper, I'm not aware that their conclusions have ever been contradicted. Can any of the other DFTers out there correct me on this? There was also a nice paper on "bond breaking" (well, stretching actually) recently by Andzelm, Sosa and Eades, J. Phys. Chem. 97(18), 4664 (1993). Not quite what Ole Swang was looking for, perhaps, as I don't believe any of the cases they discuss have the problems he described, but interesting nonetheless. Apropos excited states, see a recent paper by Daul, G\"udel and Weber, J. Chem. Phys. 98(), 4023 (1993) for a current example of what can be done. Many others are also working on this problem; but I'm writing netmail rather than a review, so I won't feel guilty about not citing them. Ross M. Dickson, Dept. of Chemistry, Univ. of Calgary, Alberta, Canada dickson@zinc.chem.ucalgary.ca From lsaw00@risque.chem.rochester.edu Tue Oct 5 09:08:40 1993 Date: Tue, 5 Oct 93 13:08:40 -0400 From: lsaw00@risque.chem.rochester.edu Message-Id: <9310051708.AA04099@risque.chem.rochester.edu> To: CHEMISTRY@ccl.net Subject: conjugation in molecular mechanics Neil Ostlund points out the dangers of simply accepting MM calculations without carefull consideration o carefull consideration of what the forcefield is doing. He gives biphenyl as an example where MM2 for instance treats the torsion angle for the single bond between the rings using the same atom types as the aromatic bond in a benzene ring. Net result a flat biphenyl. I was a little amazed at this, so I tried optimizing biphenyl in MACROMODEL which has MM2 as one of its choices with the following result: a)starting with a flat biphenyl-energy optimization gives a flat biphenyl b)starting with a 10 degree twist-energy optimization gives a 37.8 degree twist c)starting with a 89 degree twist-energy optimization gives a 37.8 degree twist The conclusion is that except for starting out flat, the MM2 forcefield will twist the bond to 37.8 degrees-a very acceptable result. But how could this be if it uses the same parameters for the single bond as an aromatic bond. So I examined the force constants for the bonds by printing out the .mmo file. Sure enough the program is smart enough to recognize that the benzene ring is a special structure with a V2 torsion parameter of 9.2 whereas the single bond(containing the same 4 atom types)has a V2 of only 1.7. I am glad to see that MM2 as implemented by MACROMODEL isn't all that bad. From HARPER_RICHARD_W@Lilly.com Tue Oct 5 07:15:36 1993 Date: Tue, 05 Oct 1993 12:15:36 -0500 (EST) From: HARPER_RICHARD_W@Lilly.com Subject: Molecular Mechanics of Conjugated Systems To: CHEMISTRY@ccl.net Message-Id: <01H3R49ONF4I0000KU@INET.D48.LILLY.COM> > Neil Ostlund correctly states that: > > The standard molecular mechanics methods (MM2, Amber, CHARMm, etc) > assign parameters on the basis of the "atom type" of the relevant > atoms involved (4 atoms,in the case of a torsion) without consideration > of the bond type. This results in the same torsional constants for the > SINGLE BOND in biphenyl at for the AROMATIC RING BONDS of Benzene!! > > Thus, all the standard methods mentioned above result in biphenyl > being planar which is unfortunate chemistry. I to have been plagued by this problem, and made the same observation relative to the deficiency in the MM2 forcefield. I solved the problem (very un-rigorously :}) by defining new atom types and a new force constant. However, I just redid the biphenyl example in MacroModel 3.0 using the MM2 forcefield included. When the calculation was continued to a sufficient level of convergence, a biphenyl with a dihedral angle for the bond joining the two benzene rings was 36.5 degrees. Do you suppose the original default parameter set of MM2 has been altered in the MacroModel version, or does MM2 do a better job than expected with this system? Dick *********************************************************************** * Richard W. Harper, Ph.D. * (317) 276-5990 Voice * * Eli Lilly & Company * (317) 276-5187 Fax * * Lilly Research Laboratories * EMail HARPER_RICHARD_W@lilly.com * * Lilly Corporate Center * or RWHARPER@acm.org * * Indianapolis, IN 46285-0444 * Compuserve 73277,1777 * *********************************************************************** From: HARPER RICHARD W (MCVAX0::WALTZ) To: VMS MAIL ADDRESSEE (IN::"CHEMISTRY@ccl.net") cc: HARPER RICHARD W (MCVAX0::WALTZ) From bobf@MSI.COM Tue Oct 5 10:04:32 1993 Message-Id: <9310051804.AA01686@lurch> From: Bob Funchess Date: Tue, 5 Oct 1993 14:04:32 -0400 Organization: Molecular Simulations Inc. To: chemistry@ccl.net Subject: conjugation in molecular mechanics On Oct 4, ostlund@hyper.com (Neil S. Ostlund) wrote: > Subject: conjugation in mol mech > > The standard molecular mechanics methods (MM2, Amber, CHARMm, etc) > assign parameters on the basis of the "atom type" of the relevant > atoms involved (4 atoms,in the case of a torsion) without consideration > of the bond type. This results in the same torsional constants for the > SINGLE BOND in biphenyl at for the AROMATIC RING BONDS of Benzene!! I can't comment about MM2 or Amber; however, the currently released version of CHARMm does not predict that biphenyl _in vacuo_ is planar. The actual angle given by a short test minimization is near 37 degrees; a vapor phase study has indicated an angle of "about 45 degrees". It's possible that an outdated version of the forcefield did predict a planar structure, or that the atoms were improperly typed, but the default typing from QUANTA with the current forcefield does produce planar phenyl rings with a 37 degree 'twist' in the single bond. Regards, Bob Funchess -- Dr. Robert B. Funchess Molecular Simulations Inc. Scientific Support 16 New England Executive Park bobf@msi.com Burlington, MA 01803-5297 (617) 229-9800 x202 FAX (617) 229-9899 From willa@cgl.ucsf.EDU Tue Oct 5 05:56:18 1993 Date: Tue, 5 Oct 93 12:56:18 -0700 Message-Id: <9310051956.AA27942@socrates.ucsf.EDU> From: willa@cgl.ucsf.edu (Willa Crowell ) To: chemistry@ccl.net Subject: ISQBP Meeting December 12-15 There are still openings for participants in the International Society of Quantum Biology and Pharmacology 1993 President's Meeting: Chemical Reactions and Molecular Recognition in Drug Design Asilomar Conference Center Pacific Grove, California December 12-15, 1993 Meeting Theme: Combining quantum mechanical and molecular mechanical methods to study chemical reactions in solution and in enzymes. Simulations on non-covalent processes of relevance in drug design, protein folding and protein-ligand complexes. Invited Speakers: Bill Jorgensen, Yale Ken Houk, UCLA Jiali Gao, SUNY, Buffalo C. Cramer, Minnesota Ken Merz, Penn State University Alain St-Amant, UCSF Arieh Warshel, USC Nina Sommers, Monsanto Dennis Underwood, Merck Gerry Maggiora, Upjohn Frank Brown, Glaxo M. Pettit, Houston Dave Pearlman, Vertex Dave Case, Scripps Barry Honig, Columbia Toshio Ichiye, Washington State Valerie Daggett, Washington Dave Spellmeyer, Chiron Martin Field, Grenoble Tentative Schedule: Monday Morning: Chemical Reactions in Solution and Enzymes I Jorgensen, Houk, Gao, Cramer Monday Evening: Chemical Reactions in Solution and Enzymes II Merz, St-Amant, Warshel Tuesday Morning: Protein Modeling and Drug Design Sommers, Underwood, Maggiora, Brown Tuesday Evening: Molecular Simulations in Solution Pettit, Pearlman, Case Wednesday Morning: Molecular Modeling: Peptides and Proteins Honig, Daggett, Ichiye, Spellmeyer For information: Contact Willa Crowell (415-476-1540) e-mail: willa@cgl.ucsf.edu or willa@ucsfvm.bitnet post: Box 0446, UCSF, SF, CA 94143-0446 Registration and Lodging Cost: $325 (payable to ISQBP) Includes Sunday, Monday & Tuesday lodging, and meals from Sunday night through Wednesday noon. Application Form: Name __________________________________ Institution: _________________________ Address: _____________________________ _____________________________ E-mail address: ______________________ If presenting poster, give title: ______________________________________________________________ ______________________________________________________________ From chiremv!andromeda!jeffb@uunet.UU.NET Tue Oct 5 02:48:09 1993 Date: Tue, 5 Oct 93 09:48:09 -0700 From: chiremv!andromeda!jeffb@uunet.UU.NET (Jeff Blaney) Message-Id: <9310051648.AA12770@andromeda> To: chemistry@ccl.net Subject: Re: Conformational Clustering > From: mikes@bioch.ox.ac.uk > Does anybody know how one goes about dividing 100 structures (say) > with the same > amino acid sequences into groups of similar structures. Many methods have been described for clustering conformations into families during the last decade or so. The RMS matrix is an effective measure of the pairwise similarities between all conformers (see Cohen, F. E., Sternberg, M. J. E. "On the Use of Chemically Derived Distance Constraints in the Prediction of Protein Structure with Myoglobin as an Example", J. Mol. Biol. 1980, 137, 9-22 and Seno, Y., Go, N. "Deoxymyoglobin Studied by the Conformational Normal Mode Analysis I. Dynamics of Globin and the Heme-Globin Interaction", J. Mol. Biol. 1990, 216, 95-109.) Cluster analysis performed on the NxN matrix containing the RMS least squares rotation/translation fit deviations for N conformers works well and has been used since the mid-80's (see Perkins, T. D. J., Barlow, D. J. "RAMBLE: A conformational search program", J. Mol. Graphics 1990, 8, 156-162). This method is also available in the program COMPARE, which was distributed with DGEOM in 1990 (QCPE Program #590). COMPARE reads a series of PDB format files and generates the RMS matrix in a format appropriate for input into ARTHUR (an old chemometrics software package) or DATADESK (Mac stats software package), which both perform hierarchical clustering. COMPARE's output format can be modified easily for other stats packages (e.g. SAS). Single or complete-linkage hierarchical clustering can be used on small problems with less than about 500 conformers; beyond this the hierarchical algorithms consume very large amounts of computer time and become impractical. Jarvis-Patrick clustering (Jarvis, R. A., Patrick, E. A. "Clustering Using a Similarity Measure Based on Shared Near Neighbors", IEEE Trans. Comp. 1973, C22, 1025-1034) is much faster than hierarchical clustering and can be applied to huge datasets (several 100,000 members). Jarvis-Patrick clustering is routinely used for clustering large chemical databases into structurally related families based on two-dimensional similarity (see Willett, P. Similarity and Clustering in Chemical Information Systems, Research Studies Press: Letchworth, 1987). Clustering 1000 conformers takes only a few seconds and requires an insignificant amount of time compared to calculating the RMS matrix. Jarvis-Patrick performs well for conformational clustering, and gives results comparable or superior to hierarchical clustering on small datasets and can be run easily on datasets that are too large for hierarchical clustering. The new release of DGEOM to QCPE (imminent...) will have a new version of COMPARE which is self- contained and includes Jarvis-Patrick clustering. Conformational clustering has also been performed directly on cartesian coordinates (Murray-Rust, P., Raftery, J. "Computer analysis of molecular geometry, Part VI: Classification of differences in conformation", J. Mol. Graphics 1985, 3, 50-59). Torsion angles are a poor choice due to their 'leverage' effect: a small torsion angle change at the beginning of a chain leads to a difference of many angstroms at the end of the chain. Yvonne Martin recently described a fast, simple approach that compares distance matrices and eliminates duplicate conformers based on any single distance difference being greater than a user-specified threshhold (Y. Martin, Meeting on Binding Sites: Characterising and Satisfying Steric and Chemical Restraints, Molecular Graphics Society, University of York, England, March 28-30, 1993). Phew. Jeff Blaney Chiron From chm6@midway.uchicago.edu Tue Oct 5 11:11:09 1993 Date: Tue, 5 Oct 93 16:11:09 CDT From: "charles h martin" Message-Id: <9310052111.AA11985@midway.uchicago.edu> To: CHEMISTRY@ccl.net Subject: System Software Netters, I am trying to find some system software to run on our SGI Power Challenge that will allocate resources to multiple uses dynamically. For example, we would like to be able to swap jobs in and out of memory at will, be able to keep accounting for suers, etc. Does anyone know of anything like this for the SGI machines? Thanks Charles Martin ================================================================== Charles H. Martin email: chm6@quads.uchicago.edu U.S. snail: c/o Freed Group The James Franck Institute and The Department of Chemistry The University of Chicago 5640 South Ellis Avenue Chicago, Illinois 60637 Work: (312) 702-3457 Fax: (312) 702-5863 ================================================================== From pbays@saintmarys.edu Tue Oct 5 12:56:56 1993 Message-Id: <199310052254.AA03125@oscsunb.ccl.net> Date: Tue, 5 Oct 93 17:56:56 -0500 From: Phil Bays To: CHEMISTRY@ccl.net, chemistry-request@ccl.net Subject: Re: conjugation in molecular mechanics Be careful in ths discussion of force field treatment of biphenyl to recognize that many programs are not smart enough to recognize when they are on the top of the energy hill. That is to say, with flat biphenyl, the program cannot decide which way to move the atoms in order best proceed toward a minimum; hence, it does not change the structure. The same will happen with an eclipsed butane. On the other hand, setting the butane torsion angle as small as 1 degree will give the program sufficient "guidance" to know how to proceed -- though again it will get stuck at the gauche local minimum. Phil Bays Saint Mary's College Notre Dame, IN 46556 pbays@saintmarys.edu From st-amant@theory.chem.uottawa.ca Tue Oct 5 15:47:39 1993 Date: Tue, 5 Oct 1993 19:47:39 -0400 From: st-amant@theory.chem.uottawa.ca (alain st-amant) Message-Id: <9310052347.AA16037@theory.chem.uottawa.ca> To: EDGECOMK@QUCDN.QueensU.CA, chemistry@ccl.net Subject: Re: DFT > This is getting interesting... > Many of my colleagues insist that DFT is essentially basis set free. > However, they do need a guess to start off and many codes 'need' > basis sets. Newer numerical codes still need something to > get them started. Has this guess part really the same level > of effect as the basis set if HF calcns? Note that there > are numerical HF codes as well. Then the choice is your grid size > ... but of course then you are no longer variational either. > Ken Edgecombe > Dept. of Chem > Queen's University DFT is far from being essentially basis set free. I've always found that you get roughly the same effects in DFT as you do in HF as you go from say minimal basis --> double zeta --> double zeta + polarization What I've found is that the DFT does however "converge" faster w.r.t. increasing the quality of your basis set beyond this point. I guess that the common wisdom is that it's easier to converge on a good description of the nodeless density than it is to converge on a good description of an ensemble of molecular orbitals. The auxiliary bases (required in codes like the one I work with) converge very quickly as well, but if not properly constructed, these auxiliary bases can be the source of error. With experience, good auxiliary bases can be constructed by quickly looking at the orbital bases and then setting up an even tempered expansion that properly spans the orbital basis' exponents. The initial guess you use to get your DFT calculation has no effect on the final answer. You only need good ones to achieve an SCF as quickly as possible. Sincerely, Alain St-Amant st-amant@theory.chem.uottawa.ca From mercie@med.cornell.edu Tue Oct 5 17:07:30 1993 Date: Tue, 5 Oct 1993 21:07:30 -0400 (EDT) From: Gustavo Mercier Subject: Re: Iron complexes w/ MM To: "Joao Otavio M.A. Lins" Message-Id: On Fri, 1 Oct 1993, Joao Otavio M.A. Lins wrote: > > Hi Netters! > > A friend of mine has asked me about the possibility to use molecular > mechanics to perform calculations on iron complexes. As a second opinion, > I'd like to hear your point of view as well as where he'll find parameters/ > force fields available to perform such calculations. Are they reliable? > Please, send replies direct to me and I'll summarize to the net. > Thanks in advance, > > Joao O.M.A. Lins > Theoretical Chemistry Group I have the following reference that gives parameters for Fe within MM2 M.G.B. Drew et al J. Chem. Soc. Dalton Trans. (1986) 1081-1086 good luck g. mercier mercie@cumc.cornell.edu From b_duke@lacebark.ntu.edu.au Wed Oct 6 06:31:00 1993 From: b_duke@lacebark.ntu.edu.au Message-Id: <9310061731.AA06451@lacebark.ntu.edu.au> Subject: Supercomputing and the transformation of science. To: CHEMISTRY@ccl.net (chemistry) Date: Wed, 6 Oct 1993 12:31:00 -0600 (CDT) G'day, I have just read a most interesting review by Tony Hey (Professor of Computation, University of Southampton, UK) in the "Times Higher Education Supplement (published in UK) of "Supercomputing and the transformation of science", by William Kaufmann and Larry Smarr, Scientific American Library (Freeman), Feb. 1993. The review is full of enthusiasm for the book, which appears to argue the case for computational science being a third methodology of science after experimental and theoretical. The book appears also to be well written and beautifully illustrated. Before I rush off and try to get it from the other side of the world - they will certainly not have it here in Darwin, although they may have it Sydney - I would like to hear of others views. Has anyone on the comp chem list seen this book? Is it as important as the reviewer is saying? Do people agree with the authors' thesis. Basically should I spend 18.95 english quid on it (probably 70 -80 Aus $ by the time it gets here)? Cheers, Brian. -- Associate Professor Brian Salter-Duke (Brian Duke) School of Chemistry and Earth Sciences, Northern Territory University, Box 40146, Casuarina, NT 0811, Australia. Phone 089-466702 e-mail: b_duke@lacebark.ntu.edu.au or b_duke@darwin.ntu.edu.au