From mw@crystal.uwa.edu.au Tue Jun 13 05:34:41 1995 Received: from uniwa.uwa.edu.au for mw@crystal.uwa.edu.au by www.ccl.net (8.6.10/930601.1506) id FAA22706; Tue, 13 Jun 1995 05:31:13 -0400 Received: from graf.crystal.uwa.edu.au (graf.crystal.uwa.edu.au [130.95.232.1]) by uniwa.uwa.edu.au (8.6.10/8.6.9) with SMTP id RAA24211 for ; Tue, 13 Jun 1995 17:29:42 +0800 Received: from pack.crystal.uwa.edu.au by graf.crystal.uwa.edu.au with SMTP (5.61+IDA+MU) id AA09445; Tue, 13 Jun 1995 18:11:59 +0800 From: mw@crystal.uwa.edu.au (Magda Wajrak) Message-Id: <9506130924.AA03701@pack> Subject: Singlet-Triplet Summary! To: CHEMISTRY@ccl.net Date: Tue, 13 Jun 95 17:24:01 WST Mailer: Elm [revision: 70.85] Dear Netters, I had few people asking me for a summary on my question regarding the singlet-triplet splitting. I posted two questions regarding singlet-triplet splitting, below are the questions and answers I received: Q1. > I would like to ask for some help in locating some articles or books > which give singlet-triplet energy splittings of some > simple sulfur and/or nitrogen containing compounds. I > especially need experimental results, but theoretical > results would also be helpfull. ANSWERS: I've been using semi-empirical methods to calculate singlet triplet gaps of aryl nitrenium ions. Here are some related references. Cramer and Dulles, JACS, 1994, 116, 9787 Gibson, Greene, and Berkowitz, JCP, 1985, 83, 4319 Ford and Scribner, JACS, 1981, 103, 4281 Glover and Scott, Tetrahedron, 1989, 45, 1763 Falvey and Cramer, Tetrahedron Lett., 1992, 33, 1705 Li, Abramovitch and Houk, JOC, 1989, 54, 2911 If you can read the world wide web Dulles and Cramer have a poster: http://hackberry.chem.niu.edu:70/0/ECCC/homepage.html Poster 59 Hope this was a help. Rick Edgington ***************************************************************************************** My group has been interested in S-T gaps in nitrenium ions for some time. Our recent efforts have focused on DFT, which is very successful in this regard. You might be interested in the following articles: Falvey, D. E.; Cramer, C. J. "Aryl- and Alkylnitrenium Ions: Singlet-Triplet Gaps via Ab Initio and Semi-Empirical Methods" Tetrahedron Lett. 1992, 33, 1705. 34. Cramer, C. J.; Dulles, F. J.; Storer, J. W.; Worthington, S. E. "Full Valence Complete Active Space SCF, Multireference CI, and Density Functional Calculations of 1A1-3B1 Singlet-Triplet Gaps for the Valence-Isoelectronic Series BH2-, CH2, NH2+, AlH2-, SiH2, PH2+, GaH2-, GeH2, and AsH2+" Chem. Phys. Lett. 1994, 218, 387. 40. Cramer, C. J.; Dulles, F. J.; Falvey, D. E. "Ab Initio Characterization of Phenylnitrenium and Phenylcarbene: Remarkably Different Properties for Isoelectronic Species" J. Am. Chem. Soc. 1994, 116, 9787. 45. Worthington, S. E.; Cramer, C. J.; Dulles, F. J. "The Electronic Structures of Aziridenium and Cyclopropylidene. Hypovalent Atoms in Three-Membered Rings" J. Phys. Chem. 1995, 99, 1462. 55. Lim, M. H.; Worthington, S. E.; Dulles, F. J.; Cramer, C. J. "Density Functional Calculations of Radicals and Diradicals" in Density-Functional Methods in Chemistry, ACS Symposium Series ###, Laird, B. B.; Ziegler, T.; Ross, R., Eds.; American Chemical Society: Washington, DC, submitted for publication. The TL paper is simply qualitative about what factors influence the gap, the remaining four are more quantitative in nature. Although all are theoretical, they contain many references to experimental work. (For the submitted book chapter, I would be happy to send you a preprint if you are interested. It covers methyl- and dimethylnitrenium, as well as the triplet and first excited state singlets of diazene). Chris *************************************************************************** Q2 > What is the singlet-triplet experimental gap data for Sulfur atom > and S2 molecule? ANSWERS: 1) Atomic species. The standard source of data for atoms is C. E. Moore, "Atomic Energy Levels", Vol. I,II,III, US National Bureau of Standards, Circular No. 467, US Government Printing Office, 1958. 2) Molecular species. Refer to the compendium of spectroscopic data on diatomic species by Gehard Herzberg. K. P. Huber and G. Herzberg, "Constants of Diatomic Molecules", van Nostrand-Reinhold (1979). Sometimes the required data can be found in the JANAF Thermochemical Tables. Herzberg only discusses states of the triplet S2 species in his mongraph "Spectra of Diatomic Molecules". In the case of atomic sulfur, the excited singlet D state is 9238.58 wavenumbers (1/cm) above the triplet P (j=0) state. There are no data on the singlet-triplet energy difference for S2 in the edition of JANAF in my office. I hope this helps. Wayne Steinmetz Carnegie Professor ***************************************************************************** My supervisor forwarded a message from you. We have published a couple of theoretical papers, which have included work on the singlet/triplet splittings of S2 and S. The experimental results we quoted were from the JANAF Thermochemical Tables, and put the splittings at (in kcal/mol): S (26.4), S2 (13.4). We had difficulties reproducing the experimental results using all sorts of levels of theory with QCISD(T) data leading to values of: S (33.4) and S2 (18.0). See our paper (J. Chem. Phys. 98, 5566 (1993) or another J. Chem. Phys. 96, 7449 (1992)). Rob. ***************************************************************************** Magdalena Wajrak From Jonathan.Connor@mailhost.mcc.ac.uk Tue Jun 13 06:19:42 1995 Received: from nessie.mcc.ac.uk for Jonathan.Connor@mailhost.mcc.ac.uk by www.ccl.net (8.6.10/930601.1506) id GAA23013; Tue, 13 Jun 1995 06:13:38 -0400 Message-Id: <199506131013.GAA23013@www.ccl.net> Received: from mailhost.mcc.ac.uk by mailhost.mcc.ac.uk id <27691-0@mailhost.mcc.ac.uk>; Tue, 13 Jun 1995 11:13:11 +0100 Subject: Theoretical Chemistry Days No 3 To: chemistry@ccl.net Date: Tue, 13 Jun 1995 11:13:09 +0100 (BST) X-Mailer: ELM [version 2.4 PL21] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 2779 From: Jonathan Connor Sender: Jonathan.Connor@mailhost.mcc.ac.uk Forwarded message: Delivery-Date: Wed, 7 Jun 1995 17:04:56 +0100 Subject: Theoretical Chemistry Days No 3 To: j.n.l.Connor@manchester.ac.uk Date: Wed, 7 Jun 1995 17:04:22 +0100 (BST) X-Mailer: ELM [version 2.4 PL21] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1853 From: Jonathan Connor Sender: Jonathan.Connor@mailhost.mcc.ac.uk Royal Society of Chemistry: Theoretical Chemistry Group Statistical Mechanics and Thermodynamics Group and EPSRC Collaborative Computational Project No. 5: Computer Simulation of Condensed Phases THEORETICAL CHEMISTRY DAYS No. 3: RECENT ADVANCES IN MOLECULAR SIMULATION A half-Day meeting to be held in the Department of Chemistry, University College, London on Wednesday 6th December 1995, from 13.30 to 17.10. Programme 1330 Chairman's Introduction, Professor J. N. L. Connor (University of Manchester) 1340 Keynote Lecture: Molecular Simulation: Recent Advances. Professor D. J. Tildesley (University of Southampton). 1430 Simulation of Polymers: Recent Advances. Professor J. H. R. Clarke (UMIST). 1455 Tea 1530 Plenary Lecture: Molecular Dynamics from First Principles: Recent Advances. Professor R. Car (Ecole Polytechnique Federale de Lausanne, Switzerland). 1620 Simulation of Stretched Crystals: Recent Advances, Professor R. M. Lynden-Bell (Queen's University, Belfast). 1645 Simulation of Liquid Crystals: Recent Advances, Doctor M. P. Allen (University of Bristol). 1710 Close Organiser: Professor J. N. L. Connor, Department of Chemistry, University of Manchester, Manchester M13 9PL. Local Organiser: Doctor Sally Price, University College London. -- ****************************************************************************** Professor J.N.L. Connor, Phone(direct line): 0161-275-4693 (national) Department of Chemistry, :+44-161-275-4693 (international) University of Manchester, Manchester M13 9PL, Phone(secretary): 0161-275-4686 or 4600 England. Fax: 0161-275-4734 or 4598 ****************************************************************************** -- ****************************************************************************** Professor J.N.L. Connor, Phone(direct line): 0161-275-4693 (national) Department of Chemistry, :+44-161-275-4693 (international) University of Manchester, Manchester M13 9PL, Phone(secretary): 0161-275-4686 or 4600 England. Fax: 0161-275-4734 or 4598 ****************************************************************************** From marek@chemi.muni.cz Tue Jun 13 08:19:43 1995 Received: from aragorn.ics.muni.cz for marek@chemi.muni.cz by www.ccl.net (8.6.10/930601.1506) id IAA23861; Tue, 13 Jun 1995 08:14:47 -0400 Received: from bilbo.chemi.muni.cz by aragorn.ics.muni.cz with SMTP id AA13689 (5.67a8/IDA-1.4.4 for ); Tue, 13 Jun 1995 14:14:19 +0200 Received: from [147.251.72.13] (rtg.chemi.muni.cz) by bilbo.chemi.muni.cz with SMTP id AA06478 (5.67b/IDA-1.4.4); Tue, 13 Jun 1995 14:14:09 +0200 Date: Tue, 13 Jun 95 14:00:57 GMT From: "Jaromir Marek" Message-Id: <62615.marek@chemi.muni.cz> X-Minuet-Version: Minuet1.0_Beta_17X Reply-To: X-Popmail-Charset: English To: chemistry@ccl.net Subject: ECP for phosphorus and chlorine Dear Colleagues, Can anyone send me a reference to the effective core potentials for chlorine and phosphorus atoms? I found the ECP data in my Turbomole manual but unfor- tunately without any reference. Thank you in advance. Yours sincerely, Jaromir *********************************************************************** * * Jaromir MAREK * * marek@vm.ics.muni.cz * dept. of inorg. chemistry * faculty of science * Masaryk University Brno * Kotlarska (street) 2 * CZ 611 37 BRNO * Czech Republic From CAVALLO@CHEMNA.DICHI.UNINA.IT Tue Jun 13 09:34:44 1995 Received: from CHEMNA.DICHI.UNINA.IT for CAVALLO@CHEMNA.DICHI.UNINA.IT by www.ccl.net (8.6.10/930601.1506) id JAA25119; Tue, 13 Jun 1995 09:30:29 -0400 From: Received: from CHEMNA.DICHI.UNINA.IT by CHEMNA.DICHI.UNINA.IT (PMDF V4.3-10 #3559) id <01HRNUPEX9XC0004OP@CHEMNA.DICHI.UNINA.IT>; Tue, 13 Jun 1995 15:30:44 +0100 (CET) Date: Tue, 13 Jun 1995 15:30:43 +0100 (CET) Subject: Prof. Bosnich Email address To: chemistry@ccl.net Message-id: <01HRNUQUX7YW0004OP@CHEMNA.DICHI.UNINA.IT> MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Content-transfer-encoding: 7BIT Dear Netters, I would need the email address of: Prof. B. Bosnich Department Of Chemistry University Of Chicago 5735 South Ellis Avenue Chicago Could somebody help me ? Thanx Dr. Luigi Cavallo Department Of Chemistry University Of Naples Naples Italy EMail cavallo@chemna.dichi.unina.it From BOBS@mdli.com Tue Jun 13 11:04:46 1995 Received: from iat.holonet.net for BOBS@mdli.com by www.ccl.net (8.6.10/930601.1506) id LAA28109; Tue, 13 Jun 1995 11:02:15 -0400 Received: from jubal.mdli.com by iat.holonet.net (BOBS@mdli.com) id IAA24532; Tue, 13 Jun 1995 08:02:14 -0700 Received: from gimli.mdli.com by jubal.mdli.com (8.6.12/9393.1) id HAA64456; Tue, 13 Jun 1995 07:56:22 -0700 Received: from mdli.com by mdli.com (PMDF V4.3-10 #6626) id <01HRNF2BPWYCQQOKYN@mdli.com>; Tue, 13 Jun 1995 08:02:28 -0800 (PST) Date: Tue, 13 Jun 1995 08:02:27 -0800 (PST) From: "Bob Snyder, x1162" Subject: CALL FOR PAPERS To: chemistry@ccl.net Message-id: <01HRNF2BPWYEQQOKYN@mdli.com> X-VMS-To: IN%"chemistry@ccl.net" X-VMS-Cc: BOBS MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Content-transfer-encoding: 7BIT Symposium: Utilization of Information in Databases of Biologically Active Compounds Location: American Chemical Society 211th National Meeting Division of Chemical Information (CINF) New Orleans, Louisiana USA Date: March 24-28, 1996 This symposium will focus on information requirements during drug discovery and how information about biologically active compounds can be used at all levels of the drug discovery process. Several invited speakers have been confirmed for the symposium. If you are interested in contributing to this symposium, please send a summary of about 200 words describing your presentation by November 1, 1995 to: Robert W. Snyder MDL Information Systems, Inc. 14600 Catalina Street San Leandro, CA 94577 USA Phone: (510) 895-1313 Fax: (510) 614-3652 Email: bobs@mdli.com Abstracts for accepted papers must be submitted by November 15, 1995 on official ACS abstract forms. For those wishing to attend, I look forward to seeing you in New Orleans. [This message has been posted to: CHEMIND-L, CHMINF-L, ACSMEDI, CCL, MOL-DIVERSITY, and ISISforum-L lists] From CUNDARIT@MSUVX1.MEMPHIS.EDU Tue Jun 13 11:49:47 1995 Received: from msuvx1.memphis.edu for CUNDARIT@MSUVX1.MEMPHIS.EDU by www.ccl.net (8.6.10/930601.1506) id LAA29569; Tue, 13 Jun 1995 11:47:59 -0400 From: Received: from MSUVX1.MEMPHIS.EDU by MSUVX1.MEMPHIS.EDU (PMDF V4.3-8 #7188) id <01HRNKNIGI3G8YELKR@MSUVX1.MEMPHIS.EDU>; Tue, 13 Jun 1995 10:48:29 -0500 (CDT) Date: Tue, 13 Jun 1995 10:48:28 -0500 (CDT) Subject: single vs double differencing in numerical calcn of Hessian To: chemistry@ccl.net Message-id: <01HRNKNIGI3I8YELKR@MSUVX1.MEMPHIS.EDU> X-VMS-To: IN%"chemistry@ccl.net" MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Content-transfer-encoding: 7BIT Fellow CCLers: As part of his research into the calculation of the vibrational spectra of transition metal complexes, one of my students is looking into the differences between single and double differencing. In both cases, the energy hessian is calculated (using the Iowa State version of GAMESS) numerically by displacing the symmetry unique atoms a small amount along the Cartesian axes. In single differencing, the displacements are along the positive x,y, & z axes, while in double differencing the diaplcements are along the positive and negative Cartesian axes. It seems to us from our reading that the general concencus is that there is little change (for example, in calculated frequencies or derived thermodyanmic quantities) in one versus the other and thus making it impractical to employ double differencing which takes roughly twice as long. However, we have yet to find a systematic study of this question for either main group or transition metal complexes. Any references to pertinent work would be most appreciated. Sincerely, Tom Cundari Associate Professor of Chemistry P.S. We are using effective core potentials and are thus limited to numerical methods for hessian calculation. +===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+=== Thomas R. Cundari Address from 3/15/95 -> ca. August: Asst. Professor of Chemistry Prof. Tom Cundari Computational Inorganic Chemistry Lab Visiting Scientist University of Memphis Cornell Theory Center Memphis, TN 38152 520 Engineering & Theory Center Bldg phone: 901-678-2629 Cornell University fax: 901-678-3447 Ithaca, New York 14853-3801 e-mail: cundarit@cc.memphis.edu phone: (607)254-8686 office: (607)254-8621 http://www.memst.edu/chemistry/umchem.html fax: (607)254-8888 e-mail: same as always +===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+=== From ravishan@swan.wcc.wesleyan.edu Tue Jun 13 14:34:48 1995 Received: from swan.wcc.wesleyan.edu for ravishan@swan.wcc.wesleyan.edu by www.ccl.net (8.6.10/930601.1506) id OAA03139; Tue, 13 Jun 1995 14:34:17 -0400 Received: by swan.wcc.wesleyan.edu (AIX 3.2/UCB 5.64/4.03) id AA17417; Tue, 13 Jun 1995 14:40:41 -0400 Date: Tue, 13 Jun 1995 14:40:41 -0400 Message-Id: <9506131840.AA17417@swan.wcc.wesleyan.edu> From: "G. Ravishanker" To: chemistry@ccl.net Subject: CD-ROM Hi I am looking for pointers on vendors who will generate CD-ROMS of software distribution for Unix machines and a ballpark estimate of the cost involved. Any help is appreciated. Ravi -- **************************************************************************** * Ganesan Ravishanker Ph: (203) 685-2104 * * Coordinator of Scientific Computing, Fax:(203) 685-2211 * * Adjunct Associate Professor(Dept. of Chem.) * * Wesleyan University e-mail:ravishan@swan.wcc.wesleyan.edu * * Middletown, CT 06459. * ****************************************************************************