From TILBROOK@chem.surrey.ac.uk Tue Feb 15 09:22:42 1994 Received: from sun2.nsfnet-relay.ac.uk for TILBROOK@chem.surrey.ac.uk by www.ccl.net (8.6.4/930601.1506) id JAA05153; Tue, 15 Feb 1994 09:19:40 -0500 Via: uk.ac.surrey; Tue, 15 Feb 1994 14:08:41 +0000 Via: central.surrey.ac.uk; Tue, 15 Feb 94 14:08:36 GMT Received: from chemcharon.chem.surrey.ac.uk by central.surrey.ac.uk with SMTP (1.37.109.8/16.2) id AA10006; Tue, 15 Feb 1994 14:08:31 GMT Received: From CHEMISTRY-1/WORKQUEUE by chemcharon.chem.surrey.ac.uk via Charon-4.0-VROOM with IPX id 100.940215140907.544; 15 Feb 94 14:28:07 +500 Message-Id: To: CHEMISTRY@ccl.net From: Dave Organization: Chemistry Department, Uni of Surrey Date: Tue, 15 Feb 1994 14:09:01 GMT Subject: Bond Stretching / Bending Force Constants for IR Priority: normal X-Mailer: WinPMail v1.0 (R1) To anybody who may be able to help. I am justing starting to work on a project which is aiming to simulate the IR spectra of organic polymers. The software I am using does this by a normal mode calculation. The problem which I am encountering is that the parameter set which I am using (Dreiding II) does not have accurate values for the bond stretching and bending force constants and thus does not give us good enough results. Does anybody know of a source of force constants for these bonds on the net? or do they know of any places that I can find extensive IR band absorption tables. At present my sole source of data is my Aldrich IR catalogue and a few simple IR spectroscopy books which give the wavenumber for the stretch or bend which I can use to calculate the force constant. Thanks in advance to anybody that can help me Regards Dave Tilbrook ********************************************************** David Tilbrook * Tel: 44 483 300 800 x 2632 Polymer Group, * x 2617 Chemistry Department, * University of Surrey, * Fax: 44 483 300 803 Guildford, Surrey, GU2 5XH * U.K. * ********************************************************** From srheller@asrr.arsusda.gov Tue Feb 15 09:46:10 1994 Received: from asrr.arsusda.gov for srheller@asrr.arsusda.gov by www.ccl.net (8.6.4/930601.1506) id IAA04818; Tue, 15 Feb 1994 08:34:17 -0500 Message-Id: <199402151334.IAA04818@www.ccl.net> Date: 15 Feb 94 08:29:00 EDT From: "STEPHEN R. HELLER" Subject: Internet Access Available at San Diego ACS Meeting To: "chemed-l" cc: "chminf-l" , "chemistry" , "orgchem" 15 February, 1994 Beilstein Information Systems, the newly created company for the distribution of the electronic products of the Beilstein Institute is pleased to announce it is making Internet access (telnet and gopher capabilities) available at their booth (#510) at the San Diego ACS meeting the week of March 13, 1994. This access to Internet, to allow meeting attendees to access their e-mail at their home computers and to perform gopher searches, is being made available as a public service by Beilstein. According to Professor Clemens Jochum, the Managing Director of Beilstein Information Systems, the new company, wants to show the chemical community that its partnership with IHS will be a leading force in the electronic information area for chemists. By providing Internet access Beilstein wants to make the Beilstein name synonymous with modern information tools and techniques. ACS attendees will be able to come to the Beilstein booth and, using equipment provided by the local Internet company, CERFnet, login to any computer in the world which is on the Internet. Attendees will be able to do this at no cost and get their e-mail or do anything they would normally do if they logged into their computer in their lab or office. If this precedent setting service proves popular with the meeting attendees, Beilstein plans to continue to provide Internet access at future ACS meetings. For further details please contact Mrs. Christiane Engelmann at 49- 69-7917-410. The essence of the above also appeared in the February 14, 1994 issue of C&E News - Science & Technology Concentrates section, page 21. From J63C002%HUSZEG11.BITNET@phem3.acs.ohio-state.edu Tue Feb 15 11:22:39 1994 Received: from phem3 for J63C002%HUSZEG11.BITNET@phem3.acs.ohio-state.edu by www.ccl.net (8.6.4/930601.1506) id KAA06679; Tue, 15 Feb 1994 10:51:35 -0500 From: Received: from HUSZEG11.BITNET (MAILER@HUSZEG11) by phem3.acs.ohio-state.edu (PMDF V4.2-13 #3557) id <01H8WU9KWSKW96VRN0@phem3.acs.ohio-state.edu>; Tue, 15 Feb 1994 10:51:28 EST Received: from HUSZEG11.BITNET (J63C002) by HUSZEG11.BITNET (Mailer R2.10 ptf000) with BSMTP id 8737; Tue, 15 Feb 94 14:13:57 +0100 Date: Tue, 15 Feb 1994 14:13:14 +0100 Subject: Reply: how to determine Cn axes To: chemistry@ccl.net Message-id: <01H8WU9KWSKY96VRN0@phem3.acs.ohio-state.edu> Content-transfer-encoding: 7BIT Dear netters There exists a program recognizing molecular orbital symmetries which can determine the principal axes of an arbitrary molecule, too. This is the program No. 484, available at QCPE (Quantum Chemistry Program Exchange). You can find the description of this program in the QCPE Bulletin 4(4), 107(1984) and Comp. & Chem. 9, 179(1985). The program is well documented and very simple to use. For determination the molecular symmetry you have to write into the input file the cartesian coordinates of the molecule. From topper@magnum.cooper.edu Tue Feb 15 11:26:58 1994 Received: from magnum.cooper.edu for topper@magnum.cooper.edu by www.ccl.net (8.6.4/930601.1506) id LAA06919; Tue, 15 Feb 1994 11:01:27 -0500 Received: by magnum.cooper.edu id AA01281 (5.65c/IDA-1.4.4 for chemistry@ccl.net); Tue, 15 Feb 1994 11:02:09 -0500 Date: Tue, 15 Feb 1994 11:02:09 -0500 From: Robert_Topper Message-Id: <199402151602.AA01281@magnum.cooper.edu> To: axh14@cac.psu.edu, chemistry@ccl.net Subject: Re: CCL:thermochemistry? Hi, I think I can supply a useful reference: (for thermochemical calculations) M.W. Chase et.al., JANAF Thermochemical Tables, 3rd ed. (American Chemical Society and American Physical Society for the National Bureau of Standards, New York, 1985). Your library probably has this in the reference section. Hope it helps! Also, in a bit of blatant self-promotion, you may find the following article of interest: RQ Topper, Q Zhang, Y.P. Liu, and D.G. Truhlar, J. Chem. Phys. 98, 4991 (1993). best to all -Robert ******************************************* Robert Q. Topper Assistant Professor of Physical Chemistry The Cooper Union for the Advancement of Science and Art Cooper Square New York, NY 10003 topper@magnum.cooper.edu (212)353-4378 FAX:(212)353-4341 ******************************************* From news@nntp-server.caltech.edu Tue Feb 15 15:27:49 1994 Received: from punisher.caltech.edu for news@nntp-server.caltech.edu by www.ccl.net (8.6.4/930601.1506) id OAA09383; Tue, 15 Feb 1994 14:34:49 -0500 Received: from gap.cco.caltech.edu by punisher.caltech.edu with SMTP (8.6.4/DEI:4.41) id LAA13010; Tue, 15 Feb 1994 11:34:45 -0800 Received: by gap.cco.caltech.edu (4.1/DEI:4.41) id AA23089; Tue, 15 Feb 94 11:34:33 PST To: mlist-chemistry@nntp-server.caltech.edu Path: terry From: terry@wag.caltech.edu (Terry R. Coley) Newsgroups: mlist.chemistry Subject: Re: CCL:OOP in Comp. Chem. and other ideas Date: 15 Feb 1994 19:34:30 GMT Organization: California Institute of Technology, Pasadena, CA Lines: 39 Message-Id: <2jr846$mhe@gap.cco.caltech.edu> References: <2jm7kg$cct@gap.cco.caltech.edu> Nntp-Posting-Host: sgi1.wag.caltech.edu A number of people have asked for more information on Tcl, the Tool Command Language created by Dr. John Ousterhout at Berkeley. There are several sources of information: 1) newsgroup comp.lang.tcl Ask your system administrator how to read this newsgroup. 2) There is a FAQ (frequently asked questions) located at harbor.ecn.purdue.edu:/pub/tcl/docs, accessible via ftp. 3) harbor.ecn.purdue.edu also mirrors the full Tcl distribution and contains perhaps the most complete collect of extensions. In brief, the Tcl language is a simple, easy to learn, yet powerful programming language. There are two *critical* features of Tcl which make it ideal for creating applications whose flow is controlled by the Tcl language: * embeddability * extensibility Embeddable means that you link the interpreter code into your program. To interpret Tcl code, you call a function to evaluate a string which is a sequence of Tcl commands. Most often, this input string comes from the command line or a script. Extensible means that you can add verbs (called commands) to the language. There is a function call which will register a new command in the Tcl interpreter. The implementation of that command is performed by a C function you write. Tcl takes care of parsing all the arguments to your newly defined command when it is encountered in an input stream. Your function is called with an argc,argv pair (argument count, argument pointer vector) which you can use to in your function. When your function completes its computation, you return and the interpreter continues to the next command. Terry R. Coley, Ph.D. Erik P. Bierwagen Goddard Research Group, Caltech Goddard Research Group, Caltech terry@wag.caltech.edu epb@wag.caltech.edu From Jorge.Medrano@UC.Edu Tue Feb 15 16:22:43 1994 Received: from ROLL.SAN.UC.EDU for Jorge.Medrano@UC.Edu by www.ccl.net (8.6.4/930601.1506) id PAA10246; Tue, 15 Feb 1994 15:35:05 -0500 From: Received: from UCBEH.SAN.UC.EDU by UCBEH.SAN.UC.EDU (PMDF V4.2-14 #4918) id <01H8X3MXS1F494K2WU@UCBEH.SAN.UC.EDU>; Tue, 15 Feb 1994 15:22:12 EST Date: Tue, 15 Feb 1994 15:22:12 -0500 (EST) Subject: infinite polyradicals To: chemistry@ccl.net Message-id: <01H8X3MY8DRM94K2WU@UCBEH.SAN.UC.EDU> X-VMS-To: IN%"chemistry@ccl.net" MIME-version: 1.0 Content-type: TEXT/PLAIN; CHARSET=US-ASCII Content-transfer-encoding: 7BIT Dear co-netters: I have been working on a quantum chemistry problem, very interesting, but with unexpected difficulties. Actually, Jimmy Stewart tried his hand on it too, and he could not solve it either. I am sending this message, "urbe et orbe", in the hope that somebody will get interested and think of something that will work, which could then easily lead to a very nice paper in collaboration. It all started with an article that appeared in C&EN, issue of August 31, 1992, page 8. There, three guys from Europe reported having measured the polymers with the lowest bandgap ever: approx. 0.5 ev. Since the subject of intrinsic conducting polymers interested me for some time, I got the full article, that appeared in Pol. Bull. 29, 119-126 (1992). The polymers measured are essentially polycroconaine and polysquaraine, and the repeat units are biradicals. The measurements are very interesting, but the authors offer no theoretical explanation for the low band gap, other than saying that the repeat units consist of alternating strong donor and acceptor moieties. They also suggest the possibility of soliton-like behavior of the charge-carriers. It occurred to me that the explanation for the low bandgap should rather lie in the existence of almost degenerate singlet and triplet states, and decided to give it a try. I used MOPAC, the AM1 parametrization, and the cluster approximation to represent the infinite quasi-1D polymer. the UHF calculation * rather easy, but as expected, the spin contamination was very high, and I thought the calculation was not reliable enough. So I decided to try the representation of the biradical provided by the keyword OPEN(2,2); that is a ROHF hamiltonian with a limited CI. (I have done this before, and it worked). To my surprise, the optimization of the geometry became totally impossible; the gradient will not decrease with any of the optimization algorithms provided in MOPAC93. If anyone is interested in getting involved, I have all the details, and the input files. I think this could lead, on the one hand to the capability to predict a whole new class of intrinsic conductors: the polyradicals; and on the other to substantial progress in the theory of organic (ferro)-magnetic materials. Is there anyone out there? Thank you for your attention. Dr. Jorge Medrano Department of Chemistry University of Cincinnati From toni@athe.WUstl.EDU Tue Feb 15 17:22:44 1994 Received: from wugate.wustl.edu for toni@athe.WUstl.EDU by www.ccl.net (8.6.4/930601.1506) id RAA11386; Tue, 15 Feb 1994 17:05:53 -0500 Received: by wugate.wustl.edu (5.67b+/WUSTL-0.3) with SMTP id AA24530; Tue, 15 Feb 1994 16:05:52 -0600 Received: by athe.WUstl.EDU (4.1/SunOS 4.1.1); Tue, 15 Feb 94 16:05:52 CST Date: Tue, 15 Feb 94 16:05:52 CST From: toni@athe.WUstl.EDU (Toni Kazic) Message-Id: <9402152205.AA12491@athe.WUstl.EDU> To: chemistry@ccl.net Subject: comparative experience with OpenGL and AVS for rendering complex 3D images Dear Netters, I am weighing alternative visualization environments for Sun/SGI machines for rendering large graphs ( <100,000 nodes and arcs) -- in essence a wireframe with curves and surfaces. Wireframe alone won't do because of the complexity of the graph -- even though it's not very big it has a lot of internal structure. I would like to hear your experience in ease of programming, maintenance, and portability; cost and support; integration into interactive systems; and visual effects (e.g., stereo, transparency, coloring). If there are other environments besides OpenGL and AVS, by all means let me hear of them. I don't wish to precipitate another discussion on the relative merits of X and Y ;-), so if people will email me I will summarize for the net. Many thanks, Toni Kazic Institute for Biomedical Computing Box 8036 Washington University School of Medicine 700 South Euclid Ave. St. Louis MO 63110 314-362-3121 314-362-0234 (fax) toni@athe.wustl.edu From jxh@ibm12.biosym.com Tue Feb 15 19:22:44 1994 Received: from ibm12.biosym.com for jxh@ibm12.biosym.com by www.ccl.net (8.6.4/930601.1506) id SAA12191; Tue, 15 Feb 1994 18:43:38 -0500 Received: by ibm12.biosym.com (AIX 3.2/UCB 5.64/4.03) id AA17737; Tue, 15 Feb 1994 15:43:09 -0800 Date: Tue, 15 Feb 1994 15:43:09 -0800 From: jxh@ibm12.biosym.com (Joerg Hill) Message-Id: <9402152343.AA17737@ibm12.biosym.com> To: CHEMISTRY@ccl.net Subject: Re: CCL:algorithm for Cn axes Since a direct answer does not work: Knowing only the atomic coordinates there is no way to find the prinicipal axes of symmetry. You need at least still the information which atoms are the same (in sense of symmetry). You can take atomic symbols, masses, atomic charges or something like that. With this information it is very easy to obtain the desired information. All physical properties of the molecule have to be invariant to the application of a symmetry operation. That means if you calculate e. g. the principal axes of inertia of your molecule (where you need the masses for), the principial axis of symmetry must be one of these axes (the other symmetry elements you can obtain in this way, too). There is a variety of programmes which does this. I know Gaussian and Turbo- mole. Joerg-R. Hill