From toukie@zui.unizh.ch Mon Aug 5 04:15:36 1996 Received: from rzusuntk.unizh.ch for toukie@zui.unizh.ch by www.ccl.net (8.7.5/950822.1) id EAA24829; Mon, 5 Aug 1996 04:14:17 -0400 (EDT) Received: from rzurs3.unizh.ch by rzusuntk.unizh.ch (4.1/SMI-4.1.9) id AA00861; Mon, 5 Aug 96 10:14:11 +0200 Received: by rzurs3.unizh.ch (AIX 3.2/UCB 5.64/4.03) id AA64314; Mon, 5 Aug 1996 10:14:10 +0200 From: toukie@zui.unizh.ch (Hr Dr. S. Shapiro) Message-Id: <9608050814.AA64314@rzurs3.unizh.ch> Subject: MOPAC 6.0 question To: chminf-l@iubvm.ucs.indiana.edu Date: Mon, 5 Aug 1996 10:14:10 +0200 (MEST) Cc: chemistry@www.ccl.net X-Mailer: ELM [version 2.4 PL24 PGP2] Content-Type: text Dear Colleagues; I wish to perform a FORCE calculation on a geometrically possible but not energetically favourable rotamer of a certain small molecule. The geometry of this molecule was first "optimised" using the keywords PM3 NOINTER EF PRECISE, and a gradient norm <0.01 was achieved without difficulty. The optimised geo- metry was then fed into MOPAC 6.0 with the optimisation flag set to "0" for all bond lengths, bond angles, and dihedral angles (because I need to have informa- tion on the "optimised" geometry without further modification) using the key- words PM3 NOINTER FORCE. The calculation went well, but I noticed that the gradient norm for the FORCE calculation was 4.3. My questions are are follows: (i) It is my understanding that a gradient norm <0.2 is considered quite acceptable for MOPAC calculations. However, for FORCE calculations there is a warning message: **GRADIENT TOO LARGE TO ALLOW FORCE MATRIX TO BE CALCULATED (LIMIT=10)**. Is a gradient norm = 8, 9, or 10 rather large, even for a FORCE calculation? If so, then why is the cut-off limit for FORCE calculations set to such an unrealistically high value as 10, rather than, say, 1 or 2? (ii) For a FORCE calculation, what are the units of the gradient norm? (iii) As stated above, for the "optimised" geometry of my structure I obtain- ed a gradient norm <0.01; yet, when subjected to a FORCE calculation, a differ- ent gradient norm value (4.3) was obtained? Why is this? Is the gradient norm for the geometry optimisation run (PM3 NOINTER EF PRECISE) different from the gradient norm for the PM3 NOINTER FORCE run? (iv) I have heard that the keyword NLLSQ can be employed to help minimise the gradient norm for a FORCE calculation. However, when I used the keywords PM3 NOINTER FORCE NLLSQ, I got an error message that MOPAC can't run with more than one geometry option. What is the proper set of keywords to do a FORCE cal- culation using the PM3 parametrisation in which the gradient norm is to mini- mised using Bartel's method? (v) If the keyword NLLSQ is inappropriate for the use to which I wish to apply it, is there another strategy that I can use to help bring down the gradi- ent norm for a FORCE calculation using a geometry-fixed structure (optimisation flags all set equal to 0) with the PM3 parametrisation? (vi) In a FORCE calculation, so long as the gradient norm is below the cut- off limit of 10, does it _really_ matter just what the value of the gradient norm is? I ought to mention that for the _most favoured_ rotamer also optimised using the keywords PM3 NOINTER EF PRECISE (resulting gradient norm <0.01), the corresponding FORCE calculation (keywords PM* NOINTER FORCE) leads to a gradient norm of 0.35. Thanks in advance to all responders. Sincerely, S. Shapiro ZH, CH toukie@zui.unizh.ch From smillefiori@dipchi.unict.it Mon Aug 5 05:15:32 1996 Received: from ns.dipchi.unict.it for smillefiori@dipchi.unict.it by www.ccl.net (8.7.5/950822.1) id EAA24987; Mon, 5 Aug 1996 04:46:47 -0400 (EDT) Received: from millefiori.dipchi.unict.it ([151.97.236.168]) by ns.dipchi.unict.it (post.office MTA v1.9.3 ID# 0-11335) with SMTP id AAA72 for ; Mon, 5 Aug 1996 10:46:05 +0100 X-Sender: smillefiori@dipchi.unict.it X-Mailer: Windows Eudora Version 1.4.4 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: chemistry@www.ccl.net From: "Millefiori Salvatore" Subject: G94W: scratch-files Date: Mon, 5 Aug 1996 10:46:05 +0100 Message-ID: <19960805094605122.AAA72@millefiori.dipchi.unict.it> Hi, I am working with Gaussian 94 for Windows (version 2.1) in Windows95 ambient with a Pentium 166 Mhz, 64 MB RAM, 512 KB cache, and 2 hard disks of 2 GB each one. I tested the possibility offered from Gaussian 94 for splitting scratch files across disks as written in Chapter 2 of the Gaussian 94 User's Reference. When I used: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1) [INPUT] %rwf=c:\gtmpc\gtmpc.rwf,100,d:\gtmp\gtmp.rwf,100 #p mp2 / 6-31g* opt 1) [OUTPUT] *********************************************** Gaussian 94: 486-Windows-G94RevB.2 3-May-1995 05-Aug-1996 *********************************************** %rwf=c:\gtmpc\gtmpc.rwf,100,d:\gtmp\gtmp.rwf,100 No file to extend for IUnit= 1 -- out of disk space. Error termination in NtrErr: NtrErr called from NtrExt. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - and when I used : - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 2) [INPUT] %rwf=c:\gtmpc\gtmpc.rwf,100,d:\gtmp\gtmp.rwf,-1 #p mp2 / 6-31g* opt it showed a Windows95's error-window with _______________________________________ Severe Error Message Execution of program c:\G94W\L101.exe failed with OS error code 24 (Too many open files) ________________________________________ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Does anybody know why ? Does anybody know solutions to my question ? Thanks to everyone. Andrea. _______________________________________________________________________ Dr. Andrea Giovanni Alparone ________ ___ (c/o Prof. Salvatore Millefiori) \___ \_____/ / Dottorato di Ricerca Scienze Chimiche, \ _/ Univ. di Catania, Italia. \______ CT\ Address: Dipartimento Scienze Chimiche, \___\ Viale A. Doria,6- 95125 CATANIA, ITALIA. Phone: 39-95-330319 (334) E-mail: smillefiori@dipchi.unict.it _______________________________________________________________________ From elazhary@theochem.uni-stuttgart.de Mon Aug 5 08:15:37 1996 Received: from artemis.rus.uni-stuttgart.de for elazhary@theochem.uni-stuttgart.de by www.ccl.net (8.7.5/950822.1) id HAA25531; Mon, 5 Aug 1996 07:31:51 -0400 (EDT) Received: from tc8.theochem.uni-stuttgart.de (tc8.theochem.uni-stuttgart.de [129.69.55.128]) by artemis.rus.uni-stuttgart.de with SMTP id NAA05492 (8.6.13/IDA-1.6 for ); Mon, 5 Aug 1996 13:31:47 +0200 Message-ID: <199608051131.NAA05492@artemis.rus.uni-stuttgart.de> Received: by tc8.theochem.uni-stuttgart.de (1.38.193.4/16.2/BelWue-2.1) id AA10556; Mon, 5 Aug 1996 13:31:46 +0200 From: "Dr. Adel El-Azhary" Subject: MCSCF freq. + scaling factors To: chemistry@www.ccl.net Date: Mon, 5 Aug 96 13:31:46 METDST Mailer: Elm [revision: 70.85] Dear Gwaltney: My impersion is that the CISD method performs worth than MP2 method at an extra computational cost. This led to a focus on the MP2 method rather than the CISD method. You can look at different papers by Schaefer which compares between the CISD and MP2 frequencies. In one of these, although not the best example, he reported the HF and CISD frequencies for thiirane and thiirene (J. Chem. Phys., 84, 4211, 1986). Concerning the MCSCF frequencies, we reported eariler, (J. Phys. Chem., 99, 12751, 1995) a comparison between the HF, MP2, MCSCF and B3LYP optimized geometries, frequencies, intensities and scale factors. The conclusion which was drawn is that the MCSCF and HF methods performed similarly due to the samll active space used in the MCSCF calculations. Adel El-Azhary Institute for Theortical chemistry Stuttgart University Stuttgart, Germany From bernd@rs5.thch.uni-bonn.de Mon Aug 5 08:48:48 1996 Received: from IBM.rhrz.uni-bonn.de for bernd@rs5.thch.uni-bonn.de by www.ccl.net (8.7.5/950822.1) id IAA25823; Mon, 5 Aug 1996 08:05:24 -0400 (EDT) Received: from rs5.thch.uni-bonn.de by IBM.rhrz.uni-bonn.de (IBM VM SMTP V2R2) with TCP; Mon, 05 Aug 96 14:04:08 MEZ Received: by rs5.thch.uni-bonn.de (AIX 3.2/UCB 5.64/4.03) id AA14725; Mon, 5 Aug 1996 14:04:48 +0200 From: bernd@rs5.thch.uni-bonn.de (Bernd Engels) Message-Id: <9608051204.AA14725@rs5.thch.uni-bonn.de> Subject: averaging of hyperfine coupling constants To: chemistry@www.ccl.net (Computational Chemistry List) Date: Mon, 5 Aug 1996 14:04:48 +0200 (MES) X-Mailer: ELM [version 2.4 PL23] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Hi, For a literature overview I am looking for studies which describe the influence of the temperature on the average between two proton hyperfine couplings, e.g. the two protons are distinguishable at 4 K but indistinguishable at 170 K. Also other centers could be averaged but protons are more often. I am mostly interested in studies which uses ab initio or semi-empirical methods but others (expecially reviews) are also highly appreciated. I know that a large number of theoretical studies have dealt with the temperature dependence of isotropic hyperfine coupling constants. (Most recently Barone and coworker discussed some nice results.) However, most of the studies are devoted to the changes in isotropic hfcc's of a single center, e.g. the temperature effect for a hydrogen center in CH_3 and not on average processes as described above. If you have any comments on the subjects, please let me know. Thank you very much for all the responses! Bernd Engels e-mail: bernd@rs5.thch.uni-bonn.de From Karsten.Malsch@uni-koeln.de Mon Aug 5 09:15:38 1996 Received: from rs3.rrz.Uni-Koeln.DE for Karsten.Malsch@uni-koeln.de by www.ccl.net (8.7.5/950822.1) id IAA26208; Mon, 5 Aug 1996 08:54:59 -0400 (EDT) Received: by rs3.rrz.Uni-Koeln.DE id AA66813 (5.67b/IDA-1.5 for chemistry@www.ccl.net); Mon, 5 Aug 1996 14:54:49 +0200 Date: Mon, 5 Aug 1996 14:54:49 +0200 (MST) From: Karsten Malsch To: chemistry@www.ccl.net Subject: positive point charges in Gaussian94 calculations Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear CCL`ers, In the past I have been trying to calculate geometries and vibrational frequencies of anions using Gaussian94 in order to compare the results with solid state IR-spectra. As I obtained overestimated bond lengths in HF calculations as well as in B3LYP-calculations I tried to construct a surrounding of positive point charges using the MASSAGE-Keyword of Gaussian94. While this worked fine with only two positive point charges my attempt to use twelve point charges (q = + 1/6) failed with Gaussian 94 producing the error message: forrtl:error:floating invalid. this did not happen during the input-section of the program, what shows that the input generally was accepted by Gaussian94. Here are my questions: 1) Did anybody observe the same problem and has an idea how to overcome it? or 2) Does anybody know a better way to take the positive surrounding of an anion in solid state into account while using Gaussian94? Thanks a lot Karsten Malsch Inst. fuer Physikalische Chemie der Universitaet zu Koeln e-mail: Karsten.Malsch@rs1.rrz.uni-koeln.de From tp@elptrs7.rug.ac.be Mon Aug 5 09:26:59 1996 Received: from elptrs7.rug.ac.be for tp@elptrs7.rug.ac.be by www.ccl.net (8.7.5/950822.1) id IAA25901; Mon, 5 Aug 1996 08:34:12 -0400 (EDT) Received: by elptrs7.rug.ac.be (AIX 4.1/UCB 5.64/4.03) id AA03132; Mon, 5 Aug 1996 14:35:28 +0200 Date: Mon, 5 Aug 1996 14:35:28 +0200 (DFT) From: "Park, Tae-Yun" To: Computational Chemistry List Subject: Help!: Strange trends of delta_Hf data for carbenium ions Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Dear all, I've been used MOPAC93 for calculating delta_Hf(Heat of formation) for many carbenium ions in gas-phase, and I found very strange trends of these values today. Comparing the values of heat of formation for various primary, secondary, and tertiary carbenium ions, I've got a reasonable results, i.e, the heat of formation values of primary carbenium ions are greater than those of secondary carbenium ions, and the values of secondary carbenuim ions are greater than those of tertiary carbenium ions, etc. However, within secondary or tertiary carbenium ions with the same number of carbon atom, I saw the values are on opposit than I expect. Please consider the following carbenium ions: + (a) C-C-C-C-C-C [ H9C4-C(+)(CH3)2 ] | C C | + (b) C-C-C-C [ (H3C)3C-C(+)(CH3)2 ] | | C C Both are tertiary carbenium ions with carbon number of 7. According to literature, the second carbenium ion (b) should be more stable than the first one (a) due to the stablization by the branched carbon atom on the alfa-positioned carbon atom that is connected to the (+)-charged carbon atom. But the results of MOPAC calculation for heat of formation for both carbenium ions are, (a) HEAT OF FORMATION = 151.93056 KCAL (b) HEAT OF FORMATION = 160.04209 KCAL which means that the first carbenium ion is more stable than the second one! What happen?? Even I have many calculated results like this, which shows exactly the opposit trend than I expect. One of them is, + C-C-C-C-C | HEAT OF FORMATION = 160.35787 KCAL C C | C-C-C-C + | HEAT OF FORMATION = 162.62280 KCAL C The keywords I used for the calculation of heat of formation are, "SYMMETRY CHARGE=1 AM1 GEO-OK EF PRECISE". Did I make a mistake in using keywords or in somewhere else? If so, how can I get an accurate and reliable results in MOPAC?? If not, does it mean that MOPAC is not accurate enough to predict the heat of formation values within same type of carbenium ions with the same carbon number? I attached my input data files of the two carbenium ions (a) and (b) written above for MOPAC calculation. PLEASE inform me of ANY suggestions/advice on this strange values, if you have any idea on this problem. Thank you VERY MUCH in advance. 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 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -------------------------------------------------------------- Input data for carbenium ions (a) and (b) -------------------------------------------------------------- SYMMETRY CHARGE=1 AM1 GEO-OK EF PRECISE r7-8.dat C 0.000000 0 0.000000 0 0.000000 0 0 0 0 C 1.523987 1 0.000000 0 0.000000 0 1 0 0 H 1.112930 1 109.468369 1 0.000000 0 1 2 0 H 1.112946 1 109.470108 1 -119.422729 1 1 2 3 H 1.112991 1 109.470108 1 119.424484 1 1 2 3 C 1.523926 1 119.999756 1 -119.356293 1 2 1 3 C 1.523926 1 120.001495 1 61.217728 1 2 1 3 C 1.522888 1 109.475357 1 179.999634 1 7 2 1 H 1.112869 1 109.471863 1 60.070694 1 7 2 1 H 1.112946 1 109.470108 1 -60.074188 1 7 2 1 C 1.522980 1 109.499832 1 179.999634 1 8 7 2 H 1.112808 1 109.405411 1 60.088181 1 8 7 2 H 1.112869 1 109.403671 1 -60.093414 1 8 7 2 C 1.522980 1 109.499832 1 -179.999634 1 11 8 7 H 1.112991 1 109.408920 1 60.095169 1 11 8 7 H 1.112991 1 109.410660 1 -60.093414 1 11 8 7 H 1.112976 1 110.001663 1 179.999634 1 14 11 8 H 1.112976 1 109.999924 1 59.922073 1 14 11 8 H 1.112976 1 110.001663 1 -59.920319 1 14 11 8 H 1.112991 1 109.470108 1 -179.999634 1 6 2 1 H 1.112930 1 109.471863 1 60.579514 1 6 2 1 H 1.112946 1 109.473618 1 -60.577759 1 6 2 1 ----------------------------------------------------------------- SYMMETRY CHARGE=1 AM1 GEO-OK EF PRECISE r7-20.dat C 0.000000 0 0.000000 0 0.000000 0 0 0 0 C 1.524002 1 0.000000 0 0.000000 0 1 0 0 H 1.112808 1 109.464874 1 0.000000 0 1 2 0 H 1.112839 1 109.466614 1 -119.419235 1 1 2 3 H 1.112808 1 109.464874 1 119.424484 1 1 2 3 C 1.523972 1 120.001495 1 179.162949 1 2 1 3 C 1.523987 1 120.001495 1 -1.379593 1 2 1 3 C 1.522964 1 109.471863 1 -179.999634 1 7 2 1 C 1.522995 1 109.471863 1 60.000748 1 7 2 1 C 1.522995 1 109.471863 1 -59.999008 1 7 2 1 H 1.112915 1 110.006912 1 179.999634 1 8 7 2 H 1.112976 1 109.998169 1 59.918564 1 8 7 2 H 1.112976 1 109.996414 1 -59.920319 1 8 7 2 H 1.112946 1 109.470108 1 -179.999634 1 6 2 1 H 1.112946 1 109.470108 1 60.576019 1 6 2 1 H 1.112946 1 109.470108 1 -60.577759 1 6 2 1 H 1.112976 1 109.998169 1 179.999634 1 10 7 2 H 1.112976 1 109.998169 1 59.920319 1 10 7 2 H 1.112961 1 109.998169 1 -59.923813 1 10 7 2 H 1.112991 1 109.999924 1 -179.999634 1 9 7 2 H 1.112961 1 109.999924 1 59.923813 1 9 7 2 H 1.112991 1 109.999924 1 -59.922073 1 9 7 2 ---------------------------------------------------------------- From elazhary@theochem.uni-stuttgart.de Mon Aug 5 10:15:55 1996 Received: from artemis.rus.uni-stuttgart.de for elazhary@theochem.uni-stuttgart.de by www.ccl.net (8.7.5/950822.1) id JAA26396; Mon, 5 Aug 1996 09:27:43 -0400 (EDT) Received: from tc8.theochem.uni-stuttgart.de (tc8.theochem.uni-stuttgart.de [129.69.55.128]) by artemis.rus.uni-stuttgart.de with SMTP id PAA07323 (8.6.13/IDA-1.6 for ); Mon, 5 Aug 1996 15:27:17 +0200 Message-ID: <199608051327.PAA07323@artemis.rus.uni-stuttgart.de> Received: by tc8.theochem.uni-stuttgart.de (1.38.193.4/16.2/BelWue-2.1) id AA11016; Mon, 5 Aug 1996 15:27:17 +0200 From: "Dr. Adel El-Azhary" Subject: MCSCF freq. + scaling factors To: chemistry@www.ccl.net Date: Mon, 5 Aug 96 15:27:17 METDST Mailer: Elm [revision: 70.85] Dear Gwaltney: My impersion is that the CISD method performs worth than MP2 method at an extra computational cost. This led to a focus on the MP2 method rather than the CISD method. You can look at different papers by Schaefer which compares between the CISD and MP2 frequencies. In one of these, although not the best example, he reported the HF and CISD frequencies for thiirane and thiirene (J. Chem. Phys., 84, 4211, 1986). Concerning the MCSCF frequencies, we reported eariler, (J. Phys. Chem., 99, 12751, 1995) a comparison between the HF, MP2, MCSCF and B3LYP optimized geometries, frequencies, intensities and scale factors. The conclusion which was drawn is that the MCSCF and HF methods performed similarly due to the samll active space used in the MCSCF calculations. Adel El-Azhary Institute for Theortical chemistry Stuttgart University Stuttgart, Germany From gaussian.com!moses@lorentzian.com Mon Aug 5 11:15:44 1996 Received: from relay5.UU.NET for gaussian.com!moses@lorentzian.com by www.ccl.net (8.7.5/950822.1) id KAA27076; Mon, 5 Aug 1996 10:41:52 -0400 (EDT) Received: from uucp4.UU.NET by relay5.UU.NET with SMTP (peer crosschecked as: uucp4.UU.NET [192.48.96.35]) id QQbblq15733; Mon, 5 Aug 1996 10:41:50 -0400 (EDT) Message-Id: Received: from m10.UUCP by uucp4.UU.NET with UUCP/RMAIL ; Mon, 5 Aug 1996 10:41:50 -0400 Received: by m10.lorentzian.com; Mon, 5 Aug 1996 10:42:56 -0400 Received: by mousse.gaussian.com; Mon, 5 Aug 1996 09:45:59 -0400 From: gaussian.com!moses@lorentzian.com (David Moses) Subject: Gaussian Workshop in Mexico City To: CHEMISTRY@www.ccl.net Date: Mon, 5 Aug 1996 09:45:59 -0400 (EDT) X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ** Gaussian Workshop in Mexico City, October 22-25 ** Gaussian, Inc. will be holding a workshop in Mexico City October 22-26 of this year. This workshop is cosponsored by Silicon Graphics, Inc. It will be held at the Division de Ciencias Basicas y Ingenieria of the Univ. Autonoma Metropolitana Iztpalapa in Mexico City, Mexico. The workshop "Introduction to Gaussian: Theory and Practice," will cover the full range of methods available in the Gaussian package with emphasis on new methods and features which make Gaussian applicable to an ever widening spectrum of research applications. Instructors for the workshop will include Dr. Mike Frisch and Dr. Doug Fox (Gaussian, Inc.) Dr. H. Bernard Schlegel (Gaussian, Inc. and Wayne State University), Dr. Gustavo Scuseria (Rice University), Dr. Jerzy Cioslowski (Florida State University) & Dr. Eric Glendenning (Indiana State University). The workshop is structured to provide an introduction to electronic structure theory as well as a hands-on review for researchers already active in the field. The workshop is open to researchers at all levels of academic, government and industrial research. The topics to be covered include the following: * Introduction to Electronic Structure Theory * Model Chemistries: A Framework for Understanding Electronic Structure Theory Results * Geometry Optimization Techniques * Electron Correlation Methods * Density Functional Theory Methods * Excited State via CI-Singles * Thermochemistry via Model Chemistries * Predicting Molecular Properties * Solvent Effects on Molecular Electronic Structure * Gaussian Utilities * Estimating Resource Requirements There will be hands-on sessions each day between the morning and afternoon lectures. Additional hands-on sessions may be available at other times. Workshop participants will be provided with access to an SGI workstation to complete exercises, experiment and/or conduct short research topics. Each workshop participants will also receive the course materials, the Gaussian 94 User's Reference and a copy of Exploring Chemistry with Electronic Structure Methods. The cost of the workshop is $200 commercial and $110 academic. For further details and application procedures, contact the workshop coordinator at Gaussian, Inc. at the phone or fax number given below, or by sending e-mail to info@gaussian.com. Best Regards, David *------------------------*------------------------*-----------------------* | David J. Moses, Ph.D. | Carnegie Office Park | info@gaussian.com | | Vice President, C.O.O. | Building Six | 412-279-6700 (Voice) | | Gaussian, Inc. | Pittsburgh, PA 15106 | 412-279-2118 (FAX) | *------------------------*------------------------*-----------------------* From tp@elptrs7.rug.ac.be Mon Aug 5 11:25:56 1996 Received: from elptrs7.rug.ac.be for tp@elptrs7.rug.ac.be by www.ccl.net (8.7.5/950822.1) id KAA26796; Mon, 5 Aug 1996 10:15:53 -0400 (EDT) Received: by elptrs7.rug.ac.be (AIX 4.1/UCB 5.64/4.03) id AA19700; Mon, 5 Aug 1996 16:17:23 +0200 Date: Mon, 5 Aug 1996 16:17:23 +0200 (DFT) From: "Park, Tae-Yun" To: Computational Chemistry List Subject: Help!(URGENT): Strange trends of delta_Hf data for carbenium ions Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII ********************************************************************** I'm sending this message more than one time since my previous try to send this message to CCL was not successful and returned with the subject "Mail Failure". Please execuse me if you have received this message twice. ********************************************************************** Dear all, I've been used MOPAC93 for calculating delta_Hf(Heat of formation) for many carbenium ions in gas-phase, and I found very strange trends of these values today. Comparing the values of heat of formation for various primary, secondary, and tertiary carbenium ions, I've got a reasonable results, i.e, the heat of formation values of primary carbenium ions are greater than those of secondary carbenium ions, and the values of secondary carbenuim ions are greater than those of tertiary carbenium ions, etc. However, within secondary or tertiary carbenium ions with the same number of carbon atom, I saw the values are on opposit than I expect. Please consider the following carbenium ions: + (a) C-C-C-C-C-C [ H9C4-C(+)(CH3)2 ] | C C | + (b) C-C-C-C [ (H3C)3C-C(+)(CH3)2 ] | | C C Both are tertiary carbenium ions with carbon number of 7. According to literature, the second carbenium ion (b) should be more stable than the first one (a) due to the stablization by the branched carbon atom on the alfa-positioned carbon atom that is connected to the (+)-charged carbon atom. But the results of MOPAC calculation for heat of formation for both carbenium ions are, (a) HEAT OF FORMATION = 151.93056 KCAL (b) HEAT OF FORMATION = 160.04209 KCAL which means that the first carbenium ion is more stable than the second one! What happen?? Even I have many calculated results like this, which shows exactly the opposit trend than I expect. One of them is, + C-C-C-C-C | HEAT OF FORMATION = 160.35787 KCAL C C | C-C-C-C + | HEAT OF FORMATION = 162.62280 KCAL C The keywords I used for the calculation of heat of formation are, "SYMMETRY CHARGE=1 AM1 GEO-OK EF PRECISE". Did I make a mistake in using keywords or in somewhere else? If so, how can I get an accurate and reliable results in MOPAC?? If not, does it mean that MOPAC is not accurate enough to predict the heat of formation values within same type of carbenium ions with the same carbon number? I attached my input data files of the two carbenium ions (a) and (b) written above for MOPAC calculation. PLEASE inform me of ANY suggestions/advice on this strange values, if you have any idea on this problem. Thank you VERY MUCH in advance. 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 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -------------------------------------------------------------- Input data for carbenium ions (a) and (b) -------------------------------------------------------------- SYMMETRY CHARGE=1 AM1 GEO-OK EF PRECISE r7-8.dat C 0.000000 0 0.000000 0 0.000000 0 0 0 0 C 1.523987 1 0.000000 0 0.000000 0 1 0 0 H 1.112930 1 109.468369 1 0.000000 0 1 2 0 H 1.112946 1 109.470108 1 -119.422729 1 1 2 3 H 1.112991 1 109.470108 1 119.424484 1 1 2 3 C 1.523926 1 119.999756 1 -119.356293 1 2 1 3 C 1.523926 1 120.001495 1 61.217728 1 2 1 3 C 1.522888 1 109.475357 1 179.999634 1 7 2 1 H 1.112869 1 109.471863 1 60.070694 1 7 2 1 H 1.112946 1 109.470108 1 -60.074188 1 7 2 1 C 1.522980 1 109.499832 1 179.999634 1 8 7 2 H 1.112808 1 109.405411 1 60.088181 1 8 7 2 H 1.112869 1 109.403671 1 -60.093414 1 8 7 2 C 1.522980 1 109.499832 1 -179.999634 1 11 8 7 H 1.112991 1 109.408920 1 60.095169 1 11 8 7 H 1.112991 1 109.410660 1 -60.093414 1 11 8 7 H 1.112976 1 110.001663 1 179.999634 1 14 11 8 H 1.112976 1 109.999924 1 59.922073 1 14 11 8 H 1.112976 1 110.001663 1 -59.920319 1 14 11 8 H 1.112991 1 109.470108 1 -179.999634 1 6 2 1 H 1.112930 1 109.471863 1 60.579514 1 6 2 1 H 1.112946 1 109.473618 1 -60.577759 1 6 2 1 ----------------------------------------------------------------- SYMMETRY CHARGE=1 AM1 GEO-OK EF PRECISE r7-20.dat C 0.000000 0 0.000000 0 0.000000 0 0 0 0 C 1.524002 1 0.000000 0 0.000000 0 1 0 0 H 1.112808 1 109.464874 1 0.000000 0 1 2 0 H 1.112839 1 109.466614 1 -119.419235 1 1 2 3 H 1.112808 1 109.464874 1 119.424484 1 1 2 3 C 1.523972 1 120.001495 1 179.162949 1 2 1 3 C 1.523987 1 120.001495 1 -1.379593 1 2 1 3 C 1.522964 1 109.471863 1 -179.999634 1 7 2 1 C 1.522995 1 109.471863 1 60.000748 1 7 2 1 C 1.522995 1 109.471863 1 -59.999008 1 7 2 1 H 1.112915 1 110.006912 1 179.999634 1 8 7 2 H 1.112976 1 109.998169 1 59.918564 1 8 7 2 H 1.112976 1 109.996414 1 -59.920319 1 8 7 2 H 1.112946 1 109.470108 1 -179.999634 1 6 2 1 H 1.112946 1 109.470108 1 60.576019 1 6 2 1 H 1.112946 1 109.470108 1 -60.577759 1 6 2 1 H 1.112976 1 109.998169 1 179.999634 1 10 7 2 H 1.112976 1 109.998169 1 59.920319 1 10 7 2 H 1.112961 1 109.998169 1 -59.923813 1 10 7 2 H 1.112991 1 109.999924 1 -179.999634 1 9 7 2 H 1.112961 1 109.999924 1 59.923813 1 9 7 2 H 1.112991 1 109.999924 1 -59.922073 1 9 7 2 ---------------------------------------------------------------- From owner-chemistry@ccl.net Mon Aug 5 12:15:42 1996 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.7.5/950822.1) id LAA27771; Mon, 5 Aug 1996 11:47:30 -0400 (EDT) Received: from scripps.edu for rickr@scripps.edu by bedrock.ccl.net (8.7.5/950822.1) id LAA24261; Mon, 5 Aug 1996 11:47:27 -0400 (EDT) Received: from aries.scripps.edu by scripps.edu (5.61/1.34) id AA28424; Mon, 5 Aug 96 08:47:27 -0700 Received: by aries.Scripps.EDU (4.1/SMI-4.1) id AA22873; Mon, 5 Aug 96 08:47:17 PDT Date: Mon, 5 Aug 96 08:47:17 PDT From: rickr@scripps.edu (Rick Ross) Message-Id: <9608051547.AA22873@aries.Scripps.EDU> To: chemistry@ccl.net Subject: Industrial App. of Comp. Chem. Symp. 2ND ANNOUNCEMENT CALL FOR PAPERS - INDUSTRIAL APPLICATIONS OF COMPUTATIONAL CHEMISTRY TO BE PRESENTED AT THE SPRING 1997 NATIONAL ACS MEETING CURRENTLY PRESENTATIONS INCLUDE SPEAKERS FROM ORGANIZATIONS INCLUDING: AMOCO, BORESKOV INSTITUTE OF CATALYSIS, DASGROUP, DOW CHEMICAL, FORD, GOODYEAR, GRONINGEN INSTITUTE, HONEYWELL, HUGHES, KODAK, LUBRIZOL, MOLECULAR SIMULATIONS, PPG INDUSTRIES, PSGVB, ROHM AND HAAS, SOUTH DAKOTA SCHOOL OF MINES, UNIVERSITY of FLORIDA, UNIVERSITY OF MASSACHUSETTS FOR PLANNING PURPOSES, IF YOU ARE INTERESTED IN PRESENTING A PAPER, PLEASE SEND NOTE OF INTEREST WITH SUBJECT AREA BY: ****AUGUST 15, 1996***** TO ANNE CHAKA (chaka@lubrizol.com) or RICK ROSS (rickr@ppg.com). Final abstracts are due October 25, 1996. COPY OF THE CALL FOR PAPERS IS BELOW: Call for Papers Industrial Applications of Computational Chemistry 1997 Spring National American Chemical Society Meeting Computers in Chemistry Division April 13-18, 1997 San Francisco, California Papers sought in all areas including applications such as catalysis, chemicals, coatings, engineering and/or theoretical chemical aspects of process design and modeling, glass, lubricants, petroleum, polymers, and other materials-orientated areas. Please send abstract (on ACS form) or initial note of interest with title/subject area to: Dr. Anne M. Chaka, The Lubrizol Corporation, 29400 Lakeland Boulevard, Wickliffe, OH 44092-2298; email: chaka@lubrizol.com. or Dr. Richard B. Ross, PPG Industries, P.O. Box 9, Allison Park, PA 15101; Voice: 412-492-5359; email: rickr@ppg.scripps.edu Abstracts due on official ACS forms no later than October 25, 1996. From owner-chemistry@ccl.net Mon Aug 5 13:16:03 1996 Received: from bedrock.ccl.net for owner-chemistry@ccl.net by www.ccl.net (8.7.5/950822.1) id MAA28030; Mon, 5 Aug 1996 12:27:20 -0400 (EDT) Received: from shiva.jussieu.fr for barbieux@ccr.jussieu.fr by bedrock.ccl.net (8.7.5/950822.1) id MAA24971; Mon, 5 Aug 1996 12:27:18 -0400 (EDT) Received: from moka.ccr.jussieu.fr (moka.ccr.jussieu.fr [134.157.1.23]) by shiva.jussieu.fr (8.7.5/jtpda-5.2) with ESMTP id SAA15958 ; Mon, 5 Aug 1996 18:27:17 +0200 (METDST) Received: from chemtob (chemtob.itodys.jussieu.fr [134.157.24.41]) by moka.ccr.jussieu.fr (8.7.5/jtpda-5.2) with SMTP id SAA109910 ; Mon, 5 Aug 1996 18:27:17 +0200 Message-ID: <32069EBB.795@ccr.jussieu.fr> Date: Mon, 05 Aug 1996 18:24:11 -0700 From: Barbieux Fabrice X-Mailer: Mozilla 2.02 (Win16; I) MIME-Version: 1.0 To: chemistry@ccl.net CC: barbieux@itodys.jussieu.fr Subject: Heat of Formation and AM1 X-URL: http://fox.pomona.claremont.edu/chem/compchem/contact.html Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hello, I'm looking for informations about heat of formation calculation by AM1. Thanks Fabrice Barbieux ITODYS 1, rue Guy de la Brosse 75005 Paris FRANCE e-mail : barbieux@itodys.jussieu.fr From vvw@dialup.oar.net Mon Aug 5 16:15:41 1996 Received: from dialup.oar.net for vvw@dialup.oar.net by www.ccl.net (8.7.5/950822.1) id PAA00022; Mon, 5 Aug 1996 15:32:08 -0400 (EDT) Received: for vvw@dialup.oar.net by dialup.oar.net (8.6.10/931123.1402) id PAA24969; Mon, 5 Aug 1996 15:29:03 -0400 Date: Mon, 5 Aug 1996 15:29:02 -0400 (EDT) From: Vernon Walatka To: chemistry@www.ccl.net Subject: Smiles Code Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII A friend is trying to complete a form that requests structural formulas in Smiles Code. What is Smiles Code? I made a couple of phone calls and searched the WWW, but no luck. Thanks. Vern From jsb2@camsoft.com Mon Aug 5 18:15:42 1996 Received: from camsoft.com for jsb2@camsoft.com by www.ccl.net (8.7.5/950822.1) id RAA00628; Mon, 5 Aug 1996 17:57:16 -0400 (EDT) From: Date: Mon, 5 Aug 96 17:57:17 EDT Received: by camsoft.com (4.1/3.1.090690-Cambridge Scientific Computing) id AA08351; Mon, 5 Aug 96 17:57:17 EDT Message-Id: <9608052157.AA08351@camsoft.com> To: chemistry@www.ccl.net, vvw@dialup.oar.net Subject: Re: CCL:Smiles Code >A friend is trying to complete a form that requests structural formulas in >Smiles Code. What is Smiles Code? I made a couple of phone calls and >searched the WWW, but no luck. SMILES is a line notation for chemical structures. It was developed by Daylight and lots of information is available from their site (http://www.daylight.com). Basically, single bonds are implied by default, and hydrogens are implicit, so CCC is propane. Branches are shown by parentheses: CC(O)C is isopropanol. Double bonds are equals signs: CC=CC is 2-butene. Ring closures are shown by matching numbers: C1CCCCC1 is cyclohexane. The rules get more complicated, but that's the general idea. SMILES is a very compact way to store chemical structures in a textual form. CS ChemDraw Net is freely available from http://www.camsoft.com/chemfinder/download.html and will allow you to create SMILES strings for most any structure you can draw. You can use SMILES strings to search WWW databases such as the one at http://chemfinder.camsoft.com (and they of course have many other non-WWW uses as well) What form is requiring SMILES strings? Jonathan Brecher CambridgeSoft Corporation jsb@camsoft.com From robert@pauli.utmb.edu Mon Aug 5 19:15:41 1996 Received: from nmr.utmb.edu for robert@pauli.utmb.edu by www.ccl.net (8.7.5/950822.1) id SAA00736; Mon, 5 Aug 1996 18:29:20 -0400 (EDT) Received: from pauli.utmb.edu by nmr.utmb.edu via SMTP (931110.SGI/930416.SGI.AUTO) for vvw@dialup.OAR.NET id AA02122; Mon, 5 Aug 96 16:37:06 -0600 Received: (from robert@localhost) by pauli.utmb.edu (950413.SGI.8.6.12/950213.SGI.AUTOCF) id RAA19681; Mon, 5 Aug 1996 17:11:44 -0500 From: "Robert Fraczkiewicz" Message-Id: <9608051711.ZM19679@pauli.utmb.edu> Date: Mon, 5 Aug 1996 17:11:43 -0500 In-Reply-To: Vernon Walatka "CCL:Smiles Code" (Aug 5, 3:29pm) References: X-Mailer: Z-Mail (3.2.3 08feb96 MediaMail) To: Vernon Walatka , chemistry@www.ccl.net Subject: Re: CCL:Smiles Code Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii On Aug 5, 3:29pm, Vernon Walatka wrote: > Subject: CCL:Smiles Code > > A friend is trying to complete a form that requests structural formulas in > Smiles Code. What is Smiles Code? I made a couple of phone calls and > searched the WWW, but no luck. > > Thanks. Dear Vernon, You can find them at http://schiele.organik.uni-erlangen.de/services/smiles.html Robert Fraczkiewicz UT Medical Branch