From zoellner@cacao.issecc.fi.cnr.it Fri Dec 9 05:18:39 1994 Received: from pc1.issecc.fi.cnr.it for zoellner@cacao.issecc.fi.cnr.it by www.ccl.net (8.6.9/930601.1506) id EAA26258; Fri, 9 Dec 1994 04:24:09 -0500 From: Message-Id: <199412090924.EAA26258@www.ccl.net> To: chemistry@ccl.net Subject: Undergraduate CC course Date: Fri Dec 09 09:18:29 1994 Greetings to the CCL Subscribers: My colleagues and I have received some funding to initiate an undergraduate course in computational chemistry. Does anyone out there have any experience in such a course for junior and senior chemistry majors? We would be happy to receive such things as syllabi, examinations, projects, and especially "pointers" concerning such a course. In addition, we would like to hear of any "follow-up" which may have been carried out to attempt to quantify the usefulness of such a course to the students after graduation (either in graduate or professional school, or in their employment). I shall be happy to post a summary of interesting replies, if any are received! Thanks very much. My e-mail address (I am on currently on sabbatical until 1 July 1995) is as follows: zoellner@cacao.issecc.fi.cnr.it After 1 July 1995, my e-mail address will be: zoellner@nauvax.ucc.nau.edu Sincerely yours, Robert W. ("Ziggy") Zoellner From noy@tci005.uibk.ac.at Fri Dec 9 07:19:09 1994 Received: from uibk.ac.at for noy@tci005.uibk.ac.at by www.ccl.net (8.6.9/930601.1506) id GAA27362; Fri, 9 Dec 1994 06:23:31 -0500 Received: from tci005.uibk.ac.at by uibk.ac.at with SMTP id AA01849 (5.65c/IDA-1.4.4 for ); Fri, 9 Dec 1994 12:22:54 +0100 Received: by tci005.uibk.ac.at (AIX 3.2/UCB 5.64/CFIBK-2e.AIX) id AA17179; Fri, 9 Dec 1994 12:22:56 +0100 From: noy@tci005.uibk.ac.at (Noy) Message-Id: <9412091122.AA17179@tci005.uibk.ac.at> Subject: Long Live CCL To: chemistry@ccl.net Date: Fri, 9 Dec 1994 12:22:56 +0100 (NFT) X-Mailer: ELM [version 2.4 PL23] Content-Type: text Content-Length: 1620 Dear Jan, On occasion of X'mas and New Year 1995, I would like to send my best wish to you. Have a nice X'mas and happy New Year. CCL, as many other discussion groups, has faced some problems from time to time, i.e., chain letters, request to move toward newsgroups, irrelevant posts etc. Many discussion groups died out quite soon from such problems or blew up with irrelevant topics but CCL has survived. I know why ? because we have a good and wise moderator. Maybe, so many people on the net have questions like me. 1) How many subscribers on CCL ? 2) Are there some prominent scientists in computational chemistry, for example, Clementi, Pople, Tildesley on-line with CCL ? 3) How old is CCL ? I wish CCL gets more and more subscribers and continue contributions to scientific society. cheers, Teerakiat ---------------------------------------------------------------------------- Teerakiat Kerdcharoen (NOY) Institute of General and Inorganic and Theoretical Chemistry Innrain 52a, A-6020 Innsbruck AUSTRIA e-mail: noy@tci2.uibk.ac.at, noy@tci.uibk.ac.at, c72454@cx.uibk.ac.at : noy@atc.atccu.chula.ac.th, noy@atc2.atccu.chula.ac.th ( Bangkok ) : c7081gag@rs6000.univie.ac.at (University of Vienna) Research : Molecular Dynamics simulations : Computer Aided Molecular/Material Designs ----------------------------------------------------------------------------- *** I have no past and no future. I just have today. From pettsj@visigoth.demon.co.uk Fri Dec 9 08:18:35 1994 Received: from post.demon.co.uk for pettsj@visigoth.demon.co.uk by www.ccl.net (8.6.9/930601.1506) id HAA28081; Fri, 9 Dec 1994 07:31:08 -0500 Received: from visigoth.demon.co.uk by post.demon.co.uk id aa19554; 9 Dec 94 12:14 GMT X-Sender: (Unverified) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 9 Dec 1994 00:15:06 +0000 To: Chemistry@ccl.net From: James Petts Subject: FDA on line? Message-ID: <9412091214.aa19554@post.demon.co.uk> Can anybody point me to the Food and Drug Administration's bulletin board, or more up-to-date access points if they exist? -- === James Petts === In the world of CD-ROM, a horse will always be an herbivorous quadruped, and there'll be endless examples to prove just that. But that world will never tell you how it feels to ride a horse. Or fall off it. From bittner@hpcf.cc.utexas.edu Fri Dec 9 10:19:14 1994 Received: from hpcf.cc.utexas.edu for bittner@hpcf.cc.utexas.edu by www.ccl.net (8.6.9/930601.1506) id JAA29218; Fri, 9 Dec 1994 09:44:27 -0500 Received: by hpcf.cc.utexas.edu (5.0/SMI-SVR4) id AA07378; Fri, 9 Dec 1994 08:44:25 +0600 From: bittner@hpcf.cc.utexas.edu (bittner) Message-Id: <9412091444.AA07378@hpcf.cc.utexas.edu> Subject: inst. normal modes of solvents To: chemistry@ccl.net Date: Fri, 9 Dec 1994 08:44:25 -0600 (CST) X-Mailer: ELM [version 2.4 PL23] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1797 Dear Fellow Netters: I'm currently developing a theory for the effect of quantum coherences between the solvent molecules and a solute particle during non-radiative relaxation. Even thought these coherences are very transient (on the order of 10 fs at most in liquids at normal temperatures) they play an important role in limiting coherent energy exchange process through extended states. I have two related questions which I wish to pose to the simulation experts. 1.) Because the coherences are short, my theory assumes that an instantaneous normal mode description of the solvent modes is sufficient for my purposes. A further approximation is that the dispersion of frequencies, i.e. the normal mode spectrum, is relatively insensitive to the electronic state of the solute molecule. Is this reasonable and does any one have data that either supports or refutes this claim? 2.) The next question is whether or not an ohmic type spectral model provides a sufficient description of the solvent modes. The particular physical system that I have in mind is that of the hydration of an excited charged ion in liquid water. Thanks in advance and I hope this stirs up discussion. Reply either to me directly or to the net. I'll report the interesting replies. Also, if someone wants a preprint of our work, I'd be happy to send some out (as soon as the papers are submitted). Regards, Eric R. Bittner ---------------------------------------------------------------------- Eric R. Bittner phone: (512)-471-1092 Dept. of Chemistry fax: (512)-471-8696 Univ. of Texas ----------------------------------------------------------------------- Wenn is das Nunstuck git und Slottermeyer? Ja! ...Beiherhund das Oder die Flipperwaldt gersput! From YSHU@UCRAC2.UCR.EDU Fri Dec 9 14:18:39 1994 Received: from UCRAC2.UCR.EDU for YSHU@UCRAC2.UCR.EDU by www.ccl.net (8.6.9/930601.1506) id OAA04178; Fri, 9 Dec 1994 14:04:41 -0500 Date: Fri, 9 Dec 1994 11:06:01 -0800 (PST) From: YSHU@UCRAC1.UCR.EDU To: chemistry@ccl.net Message-Id: <941209110601.3240e847@UCRAC1.UCR.EDU> Subject: mopac manual Dear Netters: Is anyone there know where I can find the manual for MOPAC6.0 ? Thank you for your help. Shu From BETTENS@MPS.OHIO-STATE.EDU Fri Dec 9 16:18:39 1994 Received: from ohstpw.mps.ohio-state.edu for BETTENS@MPS.OHIO-STATE.EDU by www.ccl.net (8.6.9/930601.1506) id PAA05980; Fri, 9 Dec 1994 15:32:23 -0500 From: Received: from MPS.OHIO-STATE.EDU by MPS.OHIO-STATE.EDU (PMDF V4.3-10 #5888) id <01HKG0JKZHI88Y55SS@MPS.OHIO-STATE.EDU>; Fri, 09 Dec 1994 15:32:15 -0500 (EST) Date: Fri, 09 Dec 1994 15:32:15 -0500 (EST) Subject: Open shell hydrocarbons, AM1 ROHF versus UHF To: chemistry@ccl.net Message-id: <01HKG0JL2P8Y8Y55SS@MPS.OHIO-STATE.EDU> X-VMS-To: IN%"chemistry@ccl.net" MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Content-transfer-encoding: 7BIT Dear Netters, Thanks to those of you who responded to my last posting on the 14th of November regarding spin contamination. Before summarizing these responses I would like to ask one further question which is related to my last question in the previous posting. I will then compile all responses and post a summary. My question concerns ROHF versus UHF calculations using the AM1 semiempirical model. Is anybody aware of any published work which recommends the use of either in calculating heats of formation, specifically for hydrocarbon open shell species? I have examined the original paper of Dewar, M.J.S.; Zoebisch, E.G.; Healy, E.F. and Stewart, J.J.P., J. Am. Chem. Soc., 107 (1985) 3902 where AM1 was introduced. In this work the heats of formation of 6 hydrocarbon radicals (all doublets) where compared with the experimental values. I could find no indication as to whether the reported calculations used the UHF or ROHF approaches. This is important because the calculated heats for each approach produces significantly different results. I consequently repeated the calculations on the 6 hydrocarbon radicals given in the above paper and found the following heats of formation (kcal mol^{-1}). I also give the values of S^2 and the reported heats as well as the current experimental values (from J. Phys. Chem. Ref. Data, 17 (1988) Sup. 1) for comparison below. AM1 AM1 Reported UHF S^2 ROHF AM1 Exp. Exp. - Calc.(ROHF) CH3 29.95 0.7613 31.25 31.25 34.8(3) 3.6 C2H3 60.46 0.8589 64.78 64.78 63.4(10) -1.4 C2H5 15.49 0.7619 18.14 15.48 28 10 CH2CHCH2 30.20 0.9300 38.58 38.58 39 0 (CH3)2CH 3.61 0.7622 6.80 10.07 22.3(6) 15.5 (CH3)3C -6.14 0.7623 -2.66 -2.66 11.0(6) 13.7 For C2H5 the authors seem to have reported the UHF value. I was not able to reproduce the reported result for (CH3)2CH with either the ROHF or the UHF result. I was able to reproduce the calculated heat of formation for this species given by Dewar, M.J.S. and Thiel, W., J. Am. Chem. Soc., 99 (1977) 4907, using the MNDO Hamiltonian. In this earlier work the authors explicitly stated that they used ROHF heats of formation calculated with MNDO. It is noted that for the remaining species the reported AM1 heats of formation also appear to be the ROHF values. While agreement with the experimental values are not terrific and appear particularly bad for the larger saturated hydrocarbon species, they are adequate for my purposes given that these errors can be taken as typical for calculated heats of formation of analogous but larger open shell hydrocarbon radicals. Does anybody know of any further studies, using the AM1 Hamiltonian, on radicals where the calculated heats of formation have been compared with experiment? It seems to me, from the above table, that the UHF results are not useful in comparison with the ROHF results, and that the extent of spin contamination tends to increase with molecular size and unsaturation, being close to 0.75 for the most saturated species. For instance, I repeated the calculation on triplet linear C19 given by Novoa et al., Inorganica Chemica Acta 198-200 (1992) 133, using UHF and ROHF. I obtained the same heat of formation as these authors with no assumed symmetry in the linear chain and using the UHF AM1 Hamiltonian. However, I obtained an S^2 of 4.356 (should be 2) and a ROHF heat of formation of 678.72 kcal mol^{-1}, which is greater than the UHF value by 24.17 kcal mol^{-1}! I would very much appreciate any helpful comments or literature references which deals with any of the above issues I've raised here about AM1 and its applicability of open shell systems. Regards, Ryan Bettens, OSU Physics Department, BETTENS@MPS.OHIO-STATE.edu From mizan@engin.umich.edu Fri Dec 9 21:18:39 1994 Received: from denebola.engin.umich.edu for mizan@engin.umich.edu by www.ccl.net (8.6.9/930601.1506) id UAA09828; Fri, 9 Dec 1994 20:57:18 -0500 Received: (mizan@localhost) by denebola.engin.umich.edu (8.6.8/8.6.4) id UAA24406 for CHEMISTRY@ccl.net; Fri, 9 Dec 1994 20:57:15 -0500 Date: Fri, 9 Dec 1994 20:57:15 -0500 From: "Tahmid I. Mizan" Message-Id: <199412100157.UAA24406@denebola.engin.umich.edu> To: CHEMISTRY@ccl.net Subject: ab initio hydroperoxyl radical Dear CCL'ers, Could some one point me to some references for ab initio studies of the hydroperoxyl (HO2) radical. I am particularly interested in any references that deal with charge fitting. Thanks Tahmid Mizan