From bennett@ubeclu.unibe.ch Wed Aug 28 04:20:26 1996 Received: from arwen.unibe.ch for bennett@ubeclu.unibe.ch by www.ccl.net (8.7.5/950822.1) id DAA29645; Wed, 28 Aug 1996 03:36:43 -0400 (EDT) Message-ID: Date: Wed, 28 Aug 96 09:36:29 +0100 From: "Frederick R. Bennett" Subject: G2 with reduced basis sets To: chemistry@www.ccl.net X-Mailer: VersaTerm Link v1.1 Hi, someone was asking about attempting G2 calculations with reduced basis sets. Well I found a paper addressing this issue exactly Gaussian-2 (G2) theory: Reduced basis set requirements, Curtis, Redfern, Smith, and Radom: JCP, 104 (13) 5184 Hope this helps Ciao =============================================================================== Frederick R. Bennett Papernet Address: Institut Fur anorganische, analytische und physikalische Chemie Freiestrasse 3 CH-3000 Bern 9 Switzerland Mouthnet Address: [41] (031) 631 4231 Faxnet Address [41] (031) 631 3994 Internet Address: bennett@ubeclu.unibe.ch =============================================================================== From steve@indi.aci.uni-heidelberg.de Wed Aug 28 06:20:33 1996 Received: from relay.urz.uni-heidelberg.de for steve@indi.aci.uni-heidelberg.de by www.ccl.net (8.7.5/950822.1) id FAA00323; Wed, 28 Aug 1996 05:46:39 -0400 (EDT) Received: from sun0.urz.uni-heidelberg.de (sun0.urz.uni-heidelberg.de [129.206.100.126]) by relay.urz.uni-heidelberg.de (8.7.5/8.7.4) with SMTP id LAA01778 for ; Wed, 28 Aug 1996 11:46:33 +0200 (MET DST) Received: from mondo by sun0.urz.uni-heidelberg.de (SMI-8.6/SMI-SVR4) id LAA12341; Wed, 28 Aug 1996 11:46:31 +0200 Sender: steve@indi.aci.uni-heidelberg.de Message-ID: <32241646.446B@indi.aci.uni-heidelberg.de> Date: Wed, 28 Aug 1996 11:49:58 +0200 From: Stefan Reichling X-Mailer: Mozilla 3.0 (X11; I; IRIX 5.3 IP22) MIME-Version: 1.0 To: CCL Subject: Summary on molecular crystals Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hello, I'm looking for a summary on the packing of organic molecular crystals. I know some papers from Kitaigorodskii about the subject but haven't found a summary. steve -- +---------------------------------------------------------------------+ | Stefan Reichling | | Anorganisch-Chemisches Instiut | | Tel +49-6221-548649 Universitaet Heidelberg | | Fax +49-6221-545707 69120 Heidelberg | | e-mail: steve@indi.aci.uni-heidelberg.de Germany | | www: http://ix.urz.uni-heidelberg.de/~il1 | +---------------------------------------------------------------------+ From tp@elptrs7.rug.ac.be Wed Aug 28 11:20:36 1996 Received: from elptrs7.rug.ac.be for tp@elptrs7.rug.ac.be by www.ccl.net (8.7.5/950822.1) id KAA01805; Wed, 28 Aug 1996 10:33:25 -0400 (EDT) Received: by elptrs7.rug.ac.be (AIX 4.1/UCB 5.64/4.03) id AA22272; Wed, 28 Aug 1996 16:34:32 +0200 Date: Wed, 28 Aug 1996 16:34:31 +0200 (DFT) From: "Park, Tae-Yun" To: Computational Chemistry List Subject: Formula accounting for the catalyst effect on entropy. Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear all, Please let me have your idea on the following problem. Consider the following reaction, + + C-C-C + C=C-C --->(TS)---> C-C-C-C-C (1) C and focus on the entropy differences between reactants and the transition state(TS) at 298.15K , i.e., + delta_S* = S(TS) - S(C-C-C) - S(C=C-C) (2) If reaction (1) occurs in a catalytic reaction sysem, there should be another factor(s) that influences the value of delta_S*. Under the condition that the entropy values for all the reactants and the product in *GAS-PHASE* are available, but NOT for the transition state, my question is, is it possible to construct a general formula which includes the factor(s) which can account for the catalyst effect? More clearly, is it possible to relate the delta_S* for catalytic reaction to gas-phase values of entropies for reactants and product, and some unknown parameter? I.e., delta_S* = function of [ S(reactants), S(product), parameter] If so, what does this equation look like? Should it be in a kind of added form, i.e., S(reac) +/- S(prod) +/- parameter(s) or multiplied form, i.e., parameter*S(reac) +/- parameter*S(prod) +/- ... or something else?? Any suggestion/information(books, articles..)/advice will be a great help for me. Sincerely, Park, TAE-YUN =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= State University of Ghent Laboratorium voor Petrochemische Techniek Krijgslaan 281, Blok S5 9000 Gent, Belgium TEL:+(32)-0(9)-264-4527 FAX:+(32)-0(9)-264-4999 e-mail: tp@elptrs7.rug.ac.be =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= From iok@tpci.eie.ariadne-t.gr Wed Aug 28 12:20:31 1996 Received: from tpci.eie.ariadne-t.gr for iok@tpci.eie.ariadne-t.gr by www.ccl.net (8.7.5/950822.1) id MAA02594; Wed, 28 Aug 1996 12:18:14 -0400 (EDT) Message-Id: <199608281618.MAA02594@www.ccl.net> Received: by tpci.eie.ariadne-t.gr (16.8/16.2) id AA01416; Wed, 28 Aug 96 19:32:57 +0300 From: plucky Subject: Has SomeOne Ported RASMOL to NS 2.1 ? To: CHEMISTRY@www.ccl.net Date: Wed, 28 Aug 96 19:32:56 EET Mailer: Elm [revision: 70.30] Dear Comp. Chemists, I wonder if any kind Chemist is willing to share his code for a 2.1 NeXTStep compatible Rasmol. I tried but something is screwy in me or 2.1. Thanks in advance! John Koutselas From Matthew.Harbowy@unilever.com Wed Aug 28 17:20:38 1996 Received: from gatekeeper.homecare.com for Matthew.Harbowy@unilever.com by www.ccl.net (8.7.5/950822.1) id QAA03689; Wed, 28 Aug 1996 16:25:47 -0400 (EDT) Received: from x500mhub.lo.u1388.unilever.com by gatekeeper.homecare.com (5.65v3.2/1.1.8.2/24Jan95-0439PM) id AA28138; Wed, 28 Aug 1996 21:25:16 +0100 X400-Received: by /c=GB/admd=telemail/prmd=Unilever/; Relayed; 28 Aug 1996 21:19:59 +0100 X400-Received: by mta MTAandromeda in /c=GB/admd=telemail/prmd=Unilever/; Relayed; 28 Aug 1996 21:19:59 +0100 X400-Mts-Identifier: [/c=GB/admd=telemail/prmd=Unilever/; 0533F3224A9EF045-MTAandromeda] Content-Identifier: 0533F3224A9EF045 Content-Return: Allowed X400-Content-Type: P2-1988 ( 22 ) Conversion: Allowed Original-Encoded-Information-Types: IA5-Text Priority: normal Disclose-Recipients: Prohibited Alternate-Recipient: Allowed X400-Originator: Matthew.Harbowy@unilever.com X400-Recipients: non-disclosure; Message-Id: <0533F3224A9EF045*/c=gb/admd=telemail/prmd=unilever/o=unilever/ou=andromeda/ou=ccmail/s=Harbowy/g=Matthew/@MHS> Date: 28 Aug 1996 21:19:59 +0100 From: "Matthew Harbowy" To: "chemistry@www.ccl.net" (Return requested) (Receipt notification requested), "tp@elptrs.rug.ac.be" (Return requested) (Receipt notification requested) Return-Receipt-To: "Matthew Harbowy" Subject: Re: CCL:Formula accounting for the catalyst effect on entrop Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="PART.BOUNDARY.x500test.55a1.3224a9f2.0001" --PART.BOUNDARY.x500test.55a1.3224a9f2.0001 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline RFC-822-Headers: Errors-To: ccl@www.ccl.net Precedence: bulk --PART.BOUNDARY.x500test.55a1.3224a9f2.0001 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline It is my firm belief that I cannot give your question a truly good treatment, but I will make a paltry attempt. I would refer you to Barry Carpenter's book, Determination of Organic Reaction Mechanisms, page 135-136 (section 7.2). To quote, "For reactions of higher molecularity than unimoleclar, the sign and magnitude of delta_s depend on the implied standard state, which is defined by the units of the rate constant... If one has a reference bimolecular reaction of "known" mechanism then the comparison of its activation entropy to that of some other reaction can be useful...but under no circumstances does it make sense to compare activation entropies for reactions of different molecularity." It would seem that addition of a catalyst might change the mechanism or molecularity of the reaction, and therefore your quest seems (to my limited scope) to be nonsensical. However, (also to my limited scope) it would seem that a catalyst that brings two molecules into a complex a + b + c ---> acb ---> (ab)c ts --->---> ab + c potentially reduces the degrees of freedom in the reactants relative to the transition state which might accelerate the reaction. That is, it brings reactants closer together so they react better. In this case, it might be that the entropy should decrease for the reactants relative to the transition state. What I means to say is that the change in degrees of freedom for the reference reaction from reactants to transition state a + b ---> ab (ts) ---> ab relative to the activated complex acb ---> (ab)c (ts) ---> abc is different, that you lose a degree of freedom by having to bring the two together for the reference reaction, but in the activated complex with the catalyst, you have 'already' lost a degree of freedom. But that also doesn't make sense to me, since you will lose another degree of freedom during the rearrangement acb to abc in the formation of the cyclic (ab)c. If you follow the book, section 7.3 then goes on to discuss activation volumes, which seems more relevant to your quest that activation entropies. It's hard enough for me to talk about this in the most general terms, so if you want to talk about putting numbers on any of this, it's beyond my scope. But I do recommend Carpenter's book as a good starting point for you. matt ______________________________ Reply Separator _________________________________ Subject: CCL:Formula accounting for the catalyst effect on entropy. Author: chemistry-request@www.ccl.net at INTERNET Date: 8/28/96 11:37 AM Dear all, Please let me have your idea on the following problem. Consider the following reaction, + + C-C-C + C=C-C --->(TS)---> C-C-C-C-C (1) C and focus on the entropy differences between reactants and the transition state(TS) at 298.15K , i.e., + delta_S* = S(TS) - S(C-C-C) - S(C=C-C) (2) If reaction (1) occurs in a catalytic reaction sysem, there should be another factor(s) that influences the value of delta_S*. Under the condition that the entropy values for all the reactants and the product in *GAS-PHASE* are available, but NOT for the transition state, my question is, is it possible to construct a general formula which includes the factor(s) which can account for the catalyst effect? More clearly, is it possible to relate the delta_S* for catalytic reaction to gas-phase values of entropies for reactants and product, and some unknown parameter? I.e., delta_S* = function of [ S(reactants), S(product), parameter] If so, what does this equation look like? Should it be in a kind of added form, i.e., S(reac) +/- S(prod) +/- parameter(s) or multiplied form, i.e., parameter*S(reac) +/- parameter*S(prod) +/- ... or something else?? Any suggestion/information(books, articles..)/advice will be a great help for me. Sincerely, Park, TAE-YUN =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= State University of Ghent Laboratorium voor Petrochemische Techniek Krijgslaan 281, Blok S5 9000 Gent, Belgium TEL:+(32)-0(9)-264-4527 FAX:+(32)-0(9)-264-4999 e-mail: tp@elptrs7.rug.ac.be =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -------This is added Automatically by the Software-------- -- Original Sender Envelope Address: tp@elptrs7.rug.ac.be -- Original Sender From: Address: tp@elptrs7.rug.ac.be CHEMISTRY@www.ccl.net: Everybody | CHEMISTRY-REQUEST@www.ccl.net: Coordinator MAILSERV@www.ccl.net: HELP CHEMISTRY or HELP SEARCH | Gopher: www.ccl.net 73 Anon. ftp: www.ccl.net | CHEMISTRY-SEARCH@www.ccl.net -- archive search Web: http://www.ccl.net/chemistry.html --PART.BOUNDARY.x500test.55a1.3224a9f2.0001--