From chemistry-request@server.ccl.net Tue Aug 3 13:20:05 1999 Received: from alchemy.chem.utoronto.ca (alchemy.chem.utoronto.ca [142.150.224.224]) by server.ccl.net (8.8.7/8.8.7) with ESMTP id NAA27601 for ; Tue, 3 Aug 1999 13:20:05 -0400 Received: (from elewars@localhost) by alchemy.chem.utoronto.ca (8.9.3/8.9.3) id NAA15814 for chemistry@ccl.net; Tue, 3 Aug 1999 13:13:53 -0400 (EDT) Date: Tue, 3 Aug 1999 13:13:53 -0400 (EDT) From: "E. Lewars" Message-Id: <199908031713.NAA15814@alchemy.chem.utoronto.ca> To: chemistry@ccl.net Subject: IR INTENSITIES: SUMMARY 1999 August 3 SUMMARY OF REPLIES TO QUESTION ABOUT IR INTENSITIES Reply #6 gives a ref to Raman intensities Thanks very much to all who responded to my question E. Lewars ========================= The question: 1999 July 25 INTENSITIES OF IR BANDS--HOW GOOD? A lot has been published on correction factors for the *positions* (i.e. the wavenumber values) of calculated IR bands; the canonical paper is A. P. Scott and L. Radom, J. Phys. Chem., 1996, 100, 16502. Has there been any published work on the the *relative intensities* of calculated IR bands? I mean purely empirical comparison of calc and experimental IR spectra, to see which methods give the best match to the real spectra, and how, if possible, one can correct calc intensities to match the experimental. Thanks. E. Lewars ==================== REPLIES TO QUESTION ABOUT IR INTENSITIES Note that #6 below gives a ref to Raman intensities. #1 Date: Sun, 25 Jul 1999 14:14:26 -0400 (EDT) Subject: Re: CCL:CALC IR INTENSITIES__HOW GOOD? On Sun, 25 Jul 1999, E. Lewars wrote: > INTENSITIES OF IR BANDS--HOW GOOD? Could you please send me on any references you get with respect to this issue? I am interested also :) thanks, Ruth ----------------------------------------------------------------------------- Ruth Tanner rtanner@uoguelph.ca M.Sc. Candidate in Physical Chemistry University of Guelph ---------------------------------------------------------------------------- To steal ideas from one person is plagiarism, To steal ideas from many is research. ============================================================================ #2 Sender: Bertrand.Illien@chimie.univ-nantes.fr Subject: Re: CCL:CALC IR INTENSITIES__HOW GOOD? hello E. Lewars If you get some answers, may you send it to me. thanks in advance Bertrand ------------------------- Bertrand ILLIEN Tel :(+33)(0)2 51 12 54 28 Laboratoire de Spectrochimie Fax :(+33)(0)2 51 12 54 12 Facult\351 des Sciences et Techniques, illien@chimie.univ-nantes.fr Universit\351 de Nantes 2, rue de la Houssini\350re BP 92208 44322 Nantes Cedex 3 FRANCE ============== #3 Date: Mon, 26 Jul 1999 11:02:48 +0300 (EET DST) Subject: Re: CCL:CALC IR INTENSITIES__HOW GOOD? Dear Lewars: It would be very good if you can find an answer to this problem. In short the answer to your question is no (this is an informal answer). But it might actually depend on what you exactly mean and want. You may look at the work of P. J. Stephens and the group of theoretical chemistry at Cambridge. Sorry I do not have refs. right now but I may look for some if you want. Best regards, Adel El-Azhary =========== #4 Jul 26 Jens Spanget-Larse (48) CCL:CALC RAMAN ACTIVITIES__HOW GOODCommand: Read MessageMessage 5/7 from Jens Spanget-Larsen Jul 26 '99 at 1:38 pm Organization: Roskilde Universitetscenter To: chemistry@ccl.net, "E. Lewars" Date: Mon, 26 Jul 1999 13:38:48 +0100 Subject: CCL:CALC RAMAN ACTIVITIES__HOW GOOD? Dear CCL: E. Lewars asked the following question (1999 July 25): > INTENSITIES OF IR BANDS--HOW GOOD? > > A lot has been published on correction factors for the *positions* (i.e. the > wavenumber values) of calculated IR bands; the canonical paper is A. P. Scott > and L. Radom, J. Phys. Chem., 1996, 100, 16502. > Has there been any published work on the the *relative intensities* of > calculated IR bands? I mean purely empirical comparison of calc and experiment > IR spectra, to see which methods give the best match to the real spectra, and > how, if possible, one can correct calc intensities to match the experimental. I would like to add the corresponding question concerning *Raman scattering activities*! Thank you, Yours, Jens >--< =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= JENS SPANGET-LARSEN Phone: +45 4674 2000 (RUC) Department of Chemistry +45 4674 2710 (direct) Roskilde University (RUC) Fax: +45 4674 3011 P.O.Box 260 E-Mail: JSL@virgil.ruc.dk DK-4000 Roskilde, Denmark http://www.rub.ruc.dk/dis/chem/psos/ =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= =========== #5 Jul 26 Karl Irikura (179) Re: CCL:CALC IR INTENSITIES__HOW GOOD? Date: Mon, 26 Jul 1999 16:58:16 -0400 Subject: Re: CCL:CALC IR INTENSITIES__HOW GOOD? Dear Dr. Lewars, Please summarize, especially if you find something as definitive as the Scott/Radom paper you mention. I find the following three papers. (1) Halls, M. D.; Schlegel, H. B. Journal of Chemical Physics 1998, 109, 10587-10593. (2) Lampert, H.; Mikenda, W.; Karpfen, A. J. Phys. Chem. A 1997, 101, 2254-2263. (3) Stanton, J. F.; Lipscomb, W. N.; Magers, D. H.; Bartlett, R. J. J. Chem. Phys. 1989, 90, 3241-3249. Best wishes, Karl I. ---------------------------------------------- Dr. Karl K. Irikura National Institute of Standards and Technology 100 Bureau Drive, Stop 8380 Gaithersburg, MD 20899-8380 voice: 301-975-2510 fax: 301-869-4020 e-mail: karl.irikura@nist.gov http://www.nist.gov/compchem/ ---------------------------------------------- #6 Sender: mathieu@ripault.cea.fr Date: Thu, 29 Jul 1999 11:24:41 +0200 To: "E. Lewars" , jsl@virgil.ruc.dk Subject: Re: CCL:CALC IR INTENSITIES__HOW GOOD? A recent paper: M.D. Halls & H.B. Schlegel, J. Chem. Phys. 109 (1998) p. 10587 a nd ref. 10-14 therein. In this paper, a steady improvement is noted on going from lower (HF) to higher (Adiabatic Connection DFT) levels of theory, through local and gradient correcte d functionals. The improvement in force constants accuracy on going to higher levels seems to p lay a non-negligible role. Indeed the difference between HF and B3LYP intensities is less dramatic when a common force field is used as I did in a study with normal modes obtained from CFF91 force field and quantum calculations reserved for dipole moment derivative s: cf. Int. J. Quant. Chem. 69, 705-711 (1998) > how, if possible, one can correct calc intensities to match the experimental. Such a correction is suggested by Halls & Schlegel for HF intensities. [RAMAN]: With regard to Raman data: Chem. Phys. Lett. 247, 120-125 (1995) but there are probably more recent papers. Regards -- Didier MATHIEU CEA - Le Ripault, BP 16 37260 Monts (France) Tel. 33(0)2.47.34.41.85 ========== #7 1999 July 30 George Vacek (55) Re: CCL:CALC IR INTENSITIES__HOW GOOD? ``A Systematic Theoretical Study of the Harmonic Vibrational Frequencies for Polyatomic Molecules: The Single, Double, and Perturbative Triple Excitation Coupled-Cluster [CCSD(T)] Method,'' J. R. Thomas, B. J. DeLeeuw, G. Vacek and H. F. Schaefer, J. Chem. Phys. 98, 1336 (1993). ``The Balance Between Theoretical Method and Basis Set Quality: A Systematic Study of Equilibrium Geometries, Dipole Moments, Harmonic Vibrational Frequencies, and Infrared Intensities,'' J. R. Thomas, B. J. DeLeeuw, G. Vacek, T. D. Crawford, Y. Yamaguchi and H. F. Schaefer, J. Chem. Phys. 99, 403 (1993). ``The Chemical Applicability of Standard Methods in Ab Initio Molecular Quantum Mechanics,'' in Modern Electronic Structure Theory, H. F. Schaefer, J. R. Thomas, Y. Yamaguchi, B. J. DeLeeuw and G. Vacek, Editor D. R. Yarkony (World Scientific Publishing, Singapore, 1995) pp. 3--54. =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= George Vacek + Schrodinger, Inc. (503) 299-1150 + 1500 SW First, Suite 1180 vacek@schrodinger.com + Portland, OR 97201 http://www.schrodinger.com/~vacek/ ================== #8 Subject: Re: CCL:CALC IR INTENSITIES__HOW GOOD? Hi, I don't have any denifite answer to your question, but the following literatures may be of some interest to you. Lampert, Heike; Mikenda, Werner; Karpfen, Alfred. line 1 [h for help]Molecular Geometries and Vibrational Spectra of Phenol, Benzaldehyde, and Salicylaldehyde: Experimental versus Quantum Chemical Data. J. Phys. Chem. A (1997), 101(12), 2254-2263. Nowak, Maciej J.; Lapinski, Leszek; Fulara, Jan; Les, Andrzej; Adamowicz, Ludwik. Matrix isolation IR spectroscopy of tautomeric systems and its theoretical interpretation: 2-hydroxypyridine/2(1H)-pyridinone. J. Phys. Chem. (1992), 96(4), 1562-9. Mathieu, Didier; Simonetti, Philippe. Harmonic IR spectra from empirical force fields and Ab initio dipole-moment derivatives. Int. J. Quantum Chem. (1998), 69(6), 705-711. Mathieu, Didier; Defranceschi, Mireille; Lecayon, Gerard; Grand, Andre; Delhalle, Joseph. Dependence of the vibrational frequencies and intensities on the configuration of polyacrylonitrile: an ab initio study on model oligomers. Chem. Phys. (1993), 171(1-2), 133-43. This topic is quite interesting to me also, so I would appreciate it very much if you would summarize the responses you have got. With best regards, Takanori Kanazawa ====================