From owner-chemistry@ccl.net Tue Apr 29 02:23:00 2008 From: "gnli gnli%dicp.ac.cn" To: CCL Subject: CCL: spectra Message-Id: <-36853-080429022115-17602-ukmDfRAygrSsv20jSTA2JA||server.ccl.net> X-Original-From: "gnli" Date: Tue, 29 Apr 2008 14:20:29 +0800 Sent to CCL by: "gnli" [gnli]-[dicp.ac.cn] Dear neerajmisra, Why don't you have a try using origin7.5 ? best wishes Guanna Li gnli*dicp.ac.cn -----Original Message----- > From: owner-chemistry*ccl.net [mailto:owner-chemistry*ccl.net] Sent: Tuesday, April 29, 2008 12:22 AM To: Li, Guanna Subject: CCL: spectra Sent to CCL by: "nee MI" [neerajmisra[A]hotmail.com] HOW CAN I DRAW A COMPARATIVE SIMULATED SPECTRA ALONG WITH AN OBSERVED ONE?http://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt-- No virus found in this incoming message. Checked by AVG. Version: 7.5.524 / Virus Database: 269.23.5/1400 - Release Date: 2008-4-27 9:39 From owner-chemistry@ccl.net Tue Apr 29 02:59:00 2008 From: "gnli gnli*o*dicp.ac.cn" To: CCL Subject: CCL:G: pka values with quatum methods Message-Id: <-36854-080429022958-21361-RVGVyFn5D4+sXq3EK8tCog|a|server.ccl.net> X-Original-From: "gnli" Date: Tue, 29 Apr 2008 14:29:14 +0800 Sent to CCL by: "gnli" [gnli~!~dicp.ac.cn] Dear all, I'm interesting in this aspect, and who know how to calculate a molecule under special pka value by G03 ? best wishes Guanna Li gnli,,dicp.ac.cn -----Original Message----- > From: owner-chemistry,,ccl.net [mailto:owner-chemistry,,ccl.net] Sent: Monday, April 28, 2008 11:58 PM To: Li, Guanna Subject: CCL:G: pka values with quatum methods Sent to CCL by: David Gallagher [gallagher.da^-^gmail.com] Hi Jans, A simpler method would be MOPAC2007 which predicts pKa directly and is very fast (and it's free for academics). The methodology is based on O-H bond length and partial charge from PM6 and COSMO calculations. The 109 examples* listed give an average unsigned error of 0.31 log units. There is more information* at http://www.openmopac.net/pKa_table.html and at http://www.openmopac.net/manual/index.html (select "Keywords" then "pKa"). MOPAC2007 can be downloaded at http://www.openmopac.net/downloads.html COSMOtherm is another tool that predicts pKa directly, and in a variety of solvents. COSMOtherm methodology is based on DFT and statistical thermodynamics. There is more information at http://www.cacheresearch.com/cosmo.html The only reliable way I know to determine the 'best approach', is to compare the predictions with experimental measurements for your specific classes of compounds. Indeed, calibrating predicted results with experimental data can improve the accuracy further. Regards, David Gallagher CACheResearch.com At 02:34 PM 4/27/2008, Jans H. Alzate-Morales jalzate,,utalca.cl wrote: >Sent to CCL by: "Jans H. Alzate-Morales" [jalzate(_)utalca.cl] >Dear CCL'ers, >I want to perform some pka calculations on dendrimer molecules and >it's the first time i have to face this problem. The main question >are: where can I find the equations to calculate pka values? Where >are the neccesary quatities, in the g03 output, useful to obtain the >deltaG values? >I solvated the molecules with explicit solvent. Is it the best >approach? or is it better to use the continuum solvation methods >included in gaussian package? >I'll appreciate their advice with respect this topic. > >Thank you in advance. > >Regards!!! > >Jans H. Alzate Morales >Bioinformatics and Molecular Simulation Centre >University of Talca >Talca-Chilehttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt-- No virus found in this incoming message. Checked by AVG. Version: 7.5.524 / Virus Database: 269.23.5/1400 - Release Date: 2008-4-27 9:39 From owner-chemistry@ccl.net Tue Apr 29 05:56:01 2008 From: "Rajagopalan S. r.subramanian**ipc.uni-stuttgart.de" To: CCL Subject: CCL: Seeking feedback on negative frequencies Message-Id: <-36855-080429041942-22608-s3MeTf3BJvDvEX8NgB5rVw*server.ccl.net> X-Original-From: "Rajagopalan S." Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Date: Tue, 29 Apr 2008 09:19:47 +0200 MIME-Version: 1.0 Sent to CCL by: "Rajagopalan S." [r.subramanian[-]ipc.uni-stuttgart.de] Hi many times i also use to get one or two -ve frequencies...But if it is less than 20 cm-1 one can disregard... Maurizzio Argonni m.argonni,+,gmail.com wrote: > Sent to CCL by: "Maurizzio Argonni" [m.argonni%gmail.com] > Dear CCL'ers: > > I am doing geometry optimizations on some PLP (vitamin B6) derivatives using DFT with ultra fine grids, tight convergence and a 6-31G**++ basis set. I followed them with a calculation of vibrational frequencies to ensure that indeed the structures have been minimized. All my minimizations ended normally but some of the structures show small (< 25 cm-1) negative frequencies (1 or 2 at most). > > It is my understanding that the presence of negative frequencies is a sign that a minimum has not been reached (i.e. we may have for example a saddle point). However, I recall having read in the past about people performing similar calculations and disregarding the presence of negative frequencies provided they are small enough. So, my question is whether there is some rule of thumb to know when it is safe to disregard the negative frequencies. Thanks in advance for your help. > > Maurizzio> > > -- -------------------------------------------------------------------- Rajagopalan Subramanian Institut fuer Physikalische Chemie LS II, Universitaet Stuttgart Pfaffenwaldring 55, D-70569 Stuttgart, Germany EU tel. : +49 711 685 64464, fax : +49 711 685 64443 e-mail: r.subramanian|,|ipc.uni-stuttgart.de -------------------------------------------------------------------- From owner-chemistry@ccl.net Tue Apr 29 09:08:00 2008 From: "Ernst-Walter Knapp knapp^^^chemie.fu-berlin.de" To: CCL Subject: CCL:G: pka values with quatum methods Message-Id: <-36856-080429052226-27685-qDuag5A6UJPG0xB/iFt0aA:+:server.ccl.net> X-Original-From: Ernst-Walter Knapp Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=windows-1252; format=flowed Date: Tue, 29 Apr 2008 10:17:56 +0200 MIME-Version: 1.0 Sent to CCL by: Ernst-Walter Knapp [knapp]![chemie.fu-berlin.de] Dear Guanna Li, May be you have a look at the paper: M. Schmidt am Busch and E.W. Knapp: Accurate pKa determination for a heterogeneous set of organic molecules, ChemPhysChem 5 (2004) 1513–1522. All the Best, Walter Knapp -- |---------------------------------------------------------------------| | Dr. Ernst-Walter Knapp | | Free University of Berlin Tel.: +49 30 838 54387 | | Department of Biology, Chemistry, Pharmacy Fax.: +49 30 838 56921 | | Institute of Chemistry email: knapp]_[chemie.fu-berlin.de | | Macromolecular Modeling and Simulation of Biomolecular Systems | | Takustrasse 6 | | D-14195 Berlin | | Germany www: http://agknapp.chemie.fu-berlin.de | |---------------------------------------------------------------------| gnli gnli*o*dicp.ac.cn wrote: >Sent to CCL by: "gnli" [gnli~!~dicp.ac.cn] >Dear all, >I'm interesting in this aspect, and who know how to calculate a molecule >under special pka value by G03 ? > >best wishes >Guanna Li >gnli%x%dicp.ac.cn > > > > > > > >-----Original Message----- > > >>From: owner-chemistry%x%ccl.net [mailto:owner-chemistry%x%ccl.net] >> >> >Sent: Monday, April 28, 2008 11:58 PM >To: Li, Guanna >Subject: CCL:G: pka values with quatum methods > > >Sent to CCL by: David Gallagher [gallagher.da^-^gmail.com] >Hi Jans, > >A simpler method would be MOPAC2007 which predicts pKa directly and >is very fast (and it's free for academics). The methodology is based >on O-H bond length and partial charge from PM6 and COSMO >calculations. The 109 examples* listed give an average unsigned >error of 0.31 log units. > >There is more information* at http://www.openmopac.net/pKa_table.html and at >http://www.openmopac.net/manual/index.html (select "Keywords" then >"pKa"). MOPAC2007 can be downloaded at >http://www.openmopac.net/downloads.html > >COSMOtherm is another tool that predicts pKa directly, and in a >variety of solvents. COSMOtherm methodology is based on DFT and >statistical thermodynamics. There is more information >at http://www.cacheresearch.com/cosmo.html > >The only reliable way I know to determine the 'best approach', is to >compare the predictions with experimental measurements for your >specific classes of compounds. Indeed, calibrating predicted results >with experimental data can improve the accuracy further. > >Regards, >David Gallagher >CACheResearch.com > > >At 02:34 PM 4/27/2008, Jans H. Alzate-Morales jalzate,,utalca.cl wrote: > > > >>Sent to CCL by: "Jans H. Alzate-Morales" [jalzate(_)utalca.cl] >>Dear CCL'ers, >>I want to perform some pka calculations on dendrimer molecules and >>it's the first time i have to face this problem. The main question >>are: where can I find the equations to calculate pka values? Where >>are the neccesary quatities, in the g03 output, useful to obtain the >>deltaG values? >>I solvated the molecules with explicit solvent. Is it the best >>approach? or is it better to use the continuum solvation methods >>included in gaussian package? >>I'll appreciate their advice with respect this topic. >> >>Thank you in advance. >> >>Regards!!! >> >>Jans H. Alzate Morales >>Bioinformatics and Molecular Simulation Centre >>University of Talca >>Talca-Chilehttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt-- >> >> >No virus found in this incoming message. >Checked by AVG. >Version: 7.5.524 / Virus Database: 269.23.5/1400 - Release Date: 2008-4-27 >9:39> > > > > > From owner-chemistry@ccl.net Tue Apr 29 09:52:00 2008 From: "Andy Holder holdera=umkc.edu" To: CCL Subject: CCL: negative frequencies Message-Id: <-36857-080429075923-26670-kBcj5DeJaf8KcqDlvBZjuQ ~ server.ccl.net> X-Original-From: "Andy Holder" Date: Tue, 29 Apr 2008 07:59:19 -0400 Sent to CCL by: "Andy Holder" [holdera- -umkc.edu] The decision about whether to ignore these "spurious" frequencies depends on what actual "motion" they represent. There are a number of siftware packages that will animate these for you. If they point along an alternate reaction path, then they must be eliminated. This can often be accomplished by "goosing" the geometry in that direction and reoptimizing. Further, if a pure energy minimzation is not doing the trick, then a gradient minimization (while expensive and ususally used to locate TSs) will often find a slightly better minima. Methyl rotations are often the culprit with small frequencies that won't go away, so check that. Regards, Andy Holder -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= UUUU UUU MMM MMKK KKKK CCCC | ANDREW J. HOLDER UU U MM MMK K CC CC | Professor of Comp./Org. Chem. UU U MMM M MK KK CCC | Dept. of Chemistry UU U M MM MK KK CC CC | Univ. of Missouri-Kansas City UUUUU MMM M MMKK KK CCCC | Kansas City, MO 64110 KK | holdera%a%umkc.edu K | (816)235-2293 * (816)235-6543 F -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= From owner-chemistry@ccl.net Tue Apr 29 11:37:01 2008 From: "Peter Oledzki peter|*|biosolveit.de" To: CCL Subject: CCL: Interactive Workshop on De Novo Design Message-Id: <-36858-080429113541-8519-uJA5NQpAfWyHKpeRthLrzg=-=server.ccl.net> X-Original-From: "Peter Oledzki" Date: Tue, 29 Apr 2008 11:35:38 -0400 Sent to CCL by: "Peter Oledzki" [peter(~)biosolveit.de] BioSolveIT is proud to announce its 'Interactive Workshop on Virtual Screening and De Novo Design' on June 5th 2008 - immediately following the '8th International Conference on Chemical Structures' in Noordwijkerhout, the Netherlands. The workshop will offer an occasion for expert computational chemists and novice modellers alike to learn how our software can help you in three major areas of drug discovery: Structure-Based, Ligand-Based, and De Novo Design. In particular, the workshop will cover the following topics: - Protein-Ligand Docking: The new, fully integrated FlexX 3.0 saves your time and gets you going. - Scaffold Hopping by Design: Experience yourself that core replacement is now as simple as clicking Recore. - Similarity Searching Trillions of Compounds: Learn how Pfizer and others can retrieve leads by navigating through chemistry spaces with FTrees-FS - and of course our Pipeline Pilot interfaces, the MOE interface, combinatorial docking.... all upon request. Not only is the workshop free of charge but we'll also provide complimentary software for you to take home and continue to work with. So we recommend you register immediately http://www.biosolveit.de/workshops/2008/registration.html in order to save your spot for this high-quality event. Please see our web-page www.biosolveit.de for more details. From owner-chemistry@ccl.net Tue Apr 29 13:15:00 2008 From: "Daniil Bratashov dn2010[#]gmail.com" To: CCL Subject: CCL: spectra Message-Id: <-36859-080429002953-9411-dy/YMzUo1WZFWld2orMTWA:_:server.ccl.net> X-Original-From: Daniil Bratashov Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII Date: Tue, 29 Apr 2008 07:32:18 +0400 Mime-Version: 1.0 Sent to CCL by: Daniil Bratashov [dn2010**gmail.com] On Mon, 28 Apr 2008 12:21:46 -0400 "nee MI neerajmisra++hotmail.com" wrote: > HOW CAN I DRAW A COMPARATIVE SIMULATED SPECTRA ALONG WITH AN OBSERVED > ONE? Use gaussum to extract frequency data from calculated spectra, export observed spectroscopy data into simple text format, and then use gnuplot to plot both data sets on single graphs. WBR, Daniil Bratashov From owner-chemistry@ccl.net Tue Apr 29 16:29:00 2008 From: "Dr. Daniel Glossman-Mitnik dglossman[a]gmail.com" To: CCL Subject: CCL: articles about hardness calculations Message-Id: <-36860-080429160644-18378-EbHVymuh/WfVbFbFLvF5IQ##server.ccl.net> X-Original-From: "Dr. Daniel Glossman-Mitnik" Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01C8A9FA.3EB0C730" Date: Tue, 29 Apr 2008 13:09:20 -0600 MIME-Version: 1.0 Sent to CCL by: "Dr. Daniel Glossman-Mitnik" [dglossman#%#gmail.com] This is a multi-part message in MIME format. ------=_NextPart_000_0006_01C8A9FA.3EB0C730 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear netters: =20 Some time ago, I read an article about the calculation of chemical hardness, by resorting only to the ionization potential and the HOMO and LUMO of the neutral. The idea was to calculate the EA using a combination of HOMO and LUMO, (and perhaps other orbitals), thus avoiding the calculation of the negative systems, and in turn avoiding the convergence problems. Moreover, I remember reading another article where some sort of Koopmans=B4 theorem for DFT (I know, I know=85) was considered where the IP for large molecules was calculated in terms of the HOMO and=20 LUMO of the neutral and of the positive molecule. =20 My problem is that I did not keep record of those articles, and I can not find them through searches in the literature or the WEB. If somebody is aware of these recent articles,=20 I will be grateful for sending me an e-mail with the references. =20 Thanks in advance, =20 Daniel Glossman-Mitnik=20 =20 ********************************************************************** Dr. Daniel Glossman-Mitnik Grupo NANOCOSMOS . CIMAV, SC Miguel de Cervantes 120 - Complejo Industrial Chihuahua Chihuahua, CHIH 31109 - MEXICO Tel=E9fono: 52 614 4391151 FAX: 52 614 4394852 Correo electr=F3nico: daniel.glossman(_)cimav.edu.mx =20 dglossman(_)gmail.com ********************************************************************** =20 =20 ------=_NextPart_000_0006_01C8A9FA.3EB0C730 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Dear = netters:

 

Some time ago, = I read an article about the calculation

of chemical = hardness, by resorting only to the ionization

potential and = the HOMO and LUMO of the neutral.

The idea was = to calculate the EA using a combination

of HOMO and = LUMO,=A0 (and perhaps other orbitals),

thus avoiding = the calculation of the negative systems,

and in turn = avoiding the convergence problems.

Moreover, I = remember reading another article where

some sort of = Koopmans=B4 theorem for DFT (I know, I know…)

was considered = =A0where the IP for large

molecules was calculated in terms of the HOMO and

LUMO of the = neutral and of the positive molecule.

 

My problem is = that I did not keep record of those articles,

and I can not = find them through searches in the literature

or the WEB. If = somebody is aware of these recent articles,

I will be = grateful for sending me an e-mail with the references.

 

Thanks in = advance,

 

=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =A0=A0Daniel Glossman-Mitnik

 

******************= ****************************************************

Dr. Daniel = Glossman-Mitnik

Grupo NANOCOSMOS = . CIMAV, SC

Miguel de = Cervantes 120 - Complejo Industrial Chihuahua

Chihuahua, CHIH = 31109 - MEXICO

Tel=E9fono: 52 = 614 4391151    FAX: 52 614 4394852

Correo = electr=F3nico: daniel.glossman(_)cimav.edu.mx<= /span>  

   =             &= nbsp;           &n= bsp; dglossman(_)gmail.com

*************************************= *********************************

 

 

------=_NextPart_000_0006_01C8A9FA.3EB0C730-- From owner-chemistry@ccl.net Tue Apr 29 18:22:01 2008 From: "William F. Coleman wcoleman]~[wellesley.edu" To: CCL Subject: CCL: articles about hardness calculations Message-Id: <-36861-080429182055-17269-WlpKDLEnrUOcdNqQaJA3sA]=[server.ccl.net> X-Original-From: "William F. Coleman" Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Date: Tue, 29 Apr 2008 17:48:09 -0400 MIME-Version: 1.0 Sent to CCL by: "William F. Coleman" [wcoleman(_)wellesley.edu] The absolute hardness is 1/2 the absolute value of the HOMO/LUMO difference; the absolute softness is the reciprocal of that. This definition comes from the work of Ralph Pearson. One paper that deals with this is Proceedings of the National Academy of Sciences of the United States of America, Vol. 83, No. 22 (Nov. 15, 1986), pp. 8440-8441 (available as a pdf at www.pnas.org/cgi/reprint/83/22/8440.pdf); a 1991 paper is at Chemtracts - Inorganic Chemistry, 3, 317. All of this traces back to Mulliken's ideas of electronegativity, and is also discussed in PARR, R. G., and YANG, W. (1989), "Density Functional Theory in Atoms and Molecules". Oxford University Press. New York. In recent years I have had students in my inorganic chemistry class calculate these quantities to see how well they agree with their intuition concerning hardness, softness and electronegativity. Hope this helps, Flick _______________ William F. Coleman Professor of Chemistry Wellesley College Wellesley MA 02481 on leave 2007-08 - please contact via email only wcoleman!^!wellesley.edu www.wellesley.edu/Chemistry/colemanw.html Editor, JCE WebWare and JCE Featured Molecules http://www.jce.divched.org/JCEDLib/WebWare/ http://jchemed.chem.wisc.edu/JCEWWW/Features/MonthlyMolecules/index.html From owner-chemistry@ccl.net Tue Apr 29 19:25:00 2008 From: "N. Sukumar nagams-#-rpi.edu" To: CCL Subject: CCL: articles about hardness calculations Message-Id: <-36862-080429190921-7950-q+WUQD2h2q2VMdhuJYhQXA[]server.ccl.net> X-Original-From: "N. Sukumar" Content-Disposition: inline Content-Transfer-Encoding: binary Content-Type: text/plain Date: Tue, 29 Apr 2008 19:08:53 -0400 MIME-Version: 1.0 Sent to CCL by: "N. Sukumar" [nagams-,-rpi.edu] I think the paper you are looking for is: David J. Tozer and Frank De Proft, "Computation of the Hardness and the Problem of Negative Electron Affinities in Density Functional Theory" J. Phys. Chem. A 2005, 109, 8923-8929. N. Sukumar Associate Research Professor of Chemistry and Chemical Biology Center for Biotechnology and Interdisciplinary Studies Rensselaer Polytechnic Institute http://reccr.chem.rpi.edu/ ==============Original message text=============== On Tue, 29 Apr 2008 15:09:20 EDT "Dr. Daniel Glossman-Mitnik dglossman[a]gmail.com" wrote: Dear netters: Some time ago, I read an article about the calculation of chemical hardness, by resorting only to the ionization potential and the HOMO and LUMO of the neutral. The idea was to calculate the EA using a combination of HOMO and LUMO, (and perhaps other orbitals), thus avoiding the calculation of the negative systems, and in turn avoiding the convergence problems. Moreover, I remember reading another article where some sort of Koopmans´ theorem for DFT (I know, I know…) was considered where the IP for large molecules was calculated in terms of the HOMO and LUMO of the neutral and of the positive molecule. My problem is that I did not keep record of those articles, and I can not find them through searches in the literature or the WEB. If somebody is aware of these recent articles, I will be grateful for sending me an e-mail with the references. Thanks in advance, Daniel Glossman-Mitnik ********************************************************************** Dr. Daniel Glossman-Mitnik Grupo NANOCOSMOS . CIMAV, SC Miguel de Cervantes 120 - Complejo Industrial Chihuahua Chihuahua, CHIH 31109 - MEXICO Teléfono: 52 614 4391151 FAX: 52 614 4394852 Correo electrónico: daniel.glossman ~~ cimav.edu.mx dglossman ~~ gmail.com ********************************************************************** ===========End of original message text=========== From owner-chemistry@ccl.net Tue Apr 29 19:59:01 2008 From: "Dr. Daniel Glossman-Mitnik dglossman*o*gmail.com" To: CCL Subject: CCL: articles about hardness calculations Message-Id: <-36863-080429194007-20929-bgj50NKoteMqZ8yukoU1Tg*_*server.ccl.net> X-Original-From: "Dr. Daniel Glossman-Mitnik" Content-Type: multipart/alternative; boundary="----=_NextPart_000_003E_01C8AA20.4EFCE0D0" Date: Tue, 29 Apr 2008 17:41:44 -0600 MIME-Version: 1.0 Sent to CCL by: "Dr. Daniel Glossman-Mitnik" [dglossman~~gmail.com] This is a multi-part message in MIME format. ------=_NextPart_000_003E_01C8AA20.4EFCE0D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear William F. Coleman: =20 Thanks for your fast response. I am already aware of the articles and definitions your are mentioning. However, I am looking for some recent articles related to the calculation of the EA without resorting to the the energy of the negative molecule, thus avoiding the convergence problem. =20 I have received another message with the following: David J. Tozer=20 and Frank De Proft, "Computation of the Hardness and the Problem of=20 Negative Electron Affinities in Density Functional Theory"=20 J. Phys. Chem. A 2005, 109, 8923-8929. That is the article I was looking for. =20 Best regards, =20 Dr. Daniel Glossman-Mitnik=20 =20 ********************************************************************** Dr. Daniel Glossman-Mitnik Grupo NANOCOSMOS . CIMAV, SC Miguel de Cervantes 120 - Complejo Industrial Chihuahua Chihuahua, CHIH 31109 - MEXICO Tel=E9fono: 52 614 4391151 FAX: 52 614 4394852 Correo electr=F3nico: daniel.glossman*|*cimav.edu.mx =20 dglossman*|*gmail.com ********************************************************************** =20 =20 -----Mensaje original----- De: owner-chemistry*|*ccl.net [mailto:owner-chemistry*|*ccl.net]=20 Enviado el: Martes, 29 de Abril de 2008 03:48 p.m. Para: Glossman-Mitnik, Daniel Asunto: CCL: articles about hardness calculations =20 =20 Sent to CCL by: "William F. Coleman" [wcoleman(_)wellesley.edu] The absolute hardness is 1/2 the absolute value of the HOMO/LUMO difference; the absolute softness is the reciprocal of that. =20 This definition comes from the work of Ralph Pearson. One paper that deals with this is Proceedings of the National Academy of Sciences of = the United States of America, Vol. 83, No. 22 (Nov. 15, 1986), pp. 8440-8441 (available as a pdf at www.pnas.org/cgi/reprint/83/22/8440.pdf); a 1991 paper is at Chemtracts - Inorganic Chemistry, 3, 317. =20 All of this traces back to Mulliken's ideas of electronegativity, and is also discussed in PARR, R. G., and YANG, W. (1989), "Density Functional Theory in Atoms and Molecules". Oxford University Press. New York. =20 In recent years I have had students in my inorganic chemistry class calculate these quantities to see how well they agree with their = intuition concerning hardness, softness and electronegativity. =20 Hope this helps, =20 Flick _______________ William F. Coleman Professor of Chemistry Wellesley College=20 Wellesley MA 02481 =20 on leave 2007-08 - please contact via email only=20 wcoleman|a|wellesley.edu =20 www.wellesley.edu/Chemistry/colemanw.html =20 Editor, JCE WebWare and JCE Featured Molecules http://www.jce.divched.org/JCEDLib/WebWare/ http://jchemed.chem.wisc.edu/JCEWWW/Features/MonthlyMolecules/index.html =20 =20 =20 -=3D This is automatically added to each message by the mailing script = =3D-=20http://www.ccl.net/cgi-bin/ccl/send_ccl_message =20=20 Subscribe/Unsubscribe:=20=20=20 Job: http://www.ccl.net/jobs=20=20 Search Messages: http://www.ccl.net/htdig (login: ccl, Password: = search) =20http://www.ccl.net/spammers.txt =20=20 ------=_NextPart_000_003E_01C8AA20.4EFCE0D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Dear William F. Coleman:

 

Thanks for your fast response. I am already = aware of the articles and

definitions your are mentioning. However, I = am looking for some recent

articles related to the calculation of the EA = without resorting to the

the energy of the negative molecule, thus = avoiding the convergence

problem.

 

I have received another message with the = following: David J. Tozer

and Frank De Proft, "Computation of the = Hardness and the Problem of

Negative Electron Affinities in Density = Functional Theory"

J. Phys. Chem. A 2005, 109, 8923-8929. That = is the article I was looking for.

 

Best regards,

 

=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0 =A0Dr. Daniel Glossman-Mitnik

 

**********************************************= ************************

Dr. Daniel = Glossman-Mitnik

Grupo NANOCOSMOS . CIMAV, = SC

Miguel de Cervantes 120 - Complejo Industrial Chihuahua

Chihuahua, CHIH 31109 - = MEXICO

Tel=E9fono: 52 614 4391151=A0=A0=A0 FAX: 52 = 614 4394852

Correo electr=F3nico: = daniel.glossman*|*cimav.edu.mx=A0

=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 = dglossman*|*gmail.com

*****************************************************************= *****

=A0

 

-----Mensaje original-----
De: owner-chemistry*|*ccl.net [mailto:owner-chemistry*|*ccl.net]
Enviado el: Martes, 29 de Abril de 2008 03:48 p.m.
Para: Glossman-Mitnik, Daniel
Asunto: CCL: articles about hardness calculations

 

 

Sent to CCL by: "William F. Coleman" [wcoleman(_)wellesley.edu]

The absolute hardness is 1/2 the absolute value of the = HOMO/LUMO

difference; the absolute softness is the reciprocal of = that.

 

This definition comes from the work of Ralph Pearson.=A0 One = paper that

deals with this is Proceedings of the National Academy of = Sciences of the

United States of America, Vol. 83, No. 22 (Nov. 15, 1986), pp. 8440-8441

(available as a pdf at www.pnas.org/cgi/reprint/83/22/8440.pdf); = a 1991

paper is at Chemtracts - Inorganic Chemistry, 3, = 317.

 

All of this traces back to Mulliken's ideas of = electronegativity, and is

also discussed in PARR, R. G., and YANG, W. (1989), = "Density Functional

Theory in Atoms and Molecules". Oxford University Press. = New York.

 

In recent years I have had students in my inorganic chemistry = class

calculate these quantities to see how well they agree with their intuition

concerning hardness, softness and = electronegativity.

 

Hope this helps,

 

Flick

_______________

William F. Coleman

Professor of Chemistry

Wellesley College

Wellesley MA 02481

 

on leave 2007-08 - please contact via email only =

wcoleman|a|wellesley.edu

 

www.wellesley.edu/Chemistry/colemanw.html

 

Editor, JCE WebWare and JCE Featured = Molecules

http://www.jce.divched.org/JCEDLib/WebWare/

http://jchemed.chem.wisc.edu/JCEWWW/Features/MonthlyMolecules/ind= ex.html

 

 

 

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------=_NextPart_000_003E_01C8AA20.4EFCE0D0-- From owner-chemistry@ccl.net Tue Apr 29 20:34:01 2008 From: "Dr. Daniel Glossman-Mitnik dglossman%x%gmail.com" To: CCL Subject: CCL: articles about hardness calculations Message-Id: <-36864-080429195222-26203-hnR6G9kgjLoPyytDwVW8Og{}server.ccl.net> X-Original-From: "Dr. Daniel Glossman-Mitnik" Content-Type: multipart/alternative; boundary="----=_NextPart_000_004F_01C8AA22.04EED4B0" Date: Tue, 29 Apr 2008 17:54:03 -0600 MIME-Version: 1.0 Sent to CCL by: "Dr. Daniel Glossman-Mitnik" [dglossman_._gmail.com] This is a multi-part message in MIME format. ------=_NextPart_000_004F_01C8AA22.04EED4B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear netters: =20 Thanks you all for your fast response. CCL is wonderful !!!! Indeed, the articles I was looking for are: =20 David J. Tozer and Frank De Proft, "Computation of the Hardness=20 and the Problem of Negative Electron Affinities in Density=20 Functional Theory" J. Phys. Chem. A 2005, 109, 8923-8929 =20 and =20 Ji Luo, Zeng Quan Xue, Wei Min Liu, Jin Lei Wu, and Zhong Qin Yang,=20 Koopmans=92 Theorem for Large Molecular Systems within Density=20 Functional Theory, J. Phys. Chem. A 2006, 110, 12005-12009 =20 Of course, I am looking for articles that cite these two, but this is an easier job. =20 Best regards, =20 Daniel =20 ********************************************************************** Dr. Daniel Glossman-Mitnik Grupo NANOCOSMOS . CIMAV, SC Miguel de Cervantes 120 - Complejo Industrial Chihuahua Chihuahua, CHIH 31109 - MEXICO Tel=E9fono: 52 614 4391151 FAX: 52 614 4394852 Correo electr=F3nico: daniel.glossman,cimav.edu.mx =20 dglossman,gmail.com ********************************************************************** =20 =20 ------=_NextPart_000_004F_01C8AA22.04EED4B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Dear = netters:

 

Thanks you all = for your fast response. CCL is wonderful !!!!

Indeed, the = articles I was looking for are:

 

David J. Tozer and Frank De Proft, "Computation of the Hardness

and the Problem of Negative Electron Affinities in Density =

Functional Theory" J. Phys. Chem. A 2005, 109, = 8923-8929

 

and

 

Ji Luo, Zeng Quan Xue, Wei Min Liu, =A0Jin Lei Wu, and Zhong = Qin Yang,

Koopmans’ Theorem for Large Molecular Systems within = Density

Functional Theory, J. Phys. Chem. A 2006, 110, 12005-= 12009

 

Of course, I am looking for articles that cite these two, = but this is

an easier job.

 

Best regards,

 

=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0= =A0=A0=A0 =A0Daniel

 

******************= ****************************************************

Dr. Daniel Glossman-Mitnik

Grupo NANOCOSMOS = . CIMAV, SC

Miguel de = Cervantes 120 - Complejo Industrial Chihuahua

Chihuahua, CHIH 31109 - MEXICO

Tel=E9fono: 52 = 614 4391151    FAX: 52 614 4394852

Correo electr=F3nico: = daniel.glossman,cimav.edu.mx<= /span>  

      &= nbsp;           &n= bsp;          dglossman,gmail.com

*************************************= *********************************

 

 

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