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Carnimeo I, Biczysko M, Bloino J, Barone V. Reliable structural, thermodynamic, and spectroscopic properties of organic molecules adsorbed on silicon surfaces from computational modeling: the case of glycine@Si(100). Phys Chem Chem Phys 2011; 13:16713-27. [PMID: 21858336 DOI: 10.1039/c1cp21636h] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chemisorption of glycine on Si(100) has been studied by an integrated computational strategy based on perturbative anharmonic computations employing geometries and harmonic force fields evaluated by hybrid density functionals coupled to purposely tailored basis sets. It is shown that such a strategy allows the prediction of spectroscopic properties of isolated and chemisorbed molecules with comparable accuracy, paving the route toward a detailed analysis of surface-induced changes of glycine vibrational spectra.
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Affiliation(s)
- Ivan Carnimeo
- Scuola Normale Superiore and INSTM M3-Village, Pisa, Italy
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52
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Lo PK, Lau KC. High-Level ab Initio Predictions for the Ionization Energies and Heats of Formation of Five-Membered-Ring Molecules: Thiophene, Furan, Pyrrole, 1,3-Cyclopentadiene, and Borole, C4H4X/C4H4X+ (X = S, O, NH, CH2, and BH). J Phys Chem A 2011; 115:932-9. [DOI: 10.1021/jp110499c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Po-Kam Lo
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong
| | - Kai-Chung Lau
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong
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53
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Meng K, Wang J. Anharmonic overtone and combination states of glycine and two model peptides examined by vibrational self-consistent field theory. Phys Chem Chem Phys 2011; 13:2001-13. [DOI: 10.1039/c0cp01177k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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54
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DeYonker NJ, Wilson BR, Pierpont AW, Cundari TR, Wilson AK. Towards the intrinsic error of the correlation consistent Composite Approach (ccCA). Mol Phys 2010. [DOI: 10.1080/00268970902744359] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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55
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Yang Q, Xie B, Li Q, Zhao K. Density Functional Theory Study of Hydrogen Bonding Dimers with 4‐Pyridinecarboxylic Acid Hydrazine. CHINESE J CHEM 2010. [DOI: 10.1002/cjoc.201090310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Qiongfen Yang
- College of Chemistry and Material Science, Sichuan Normal University, Key Laboratory of Advanced Functional Materials, Sichuan Province Higher Education System, Chengdu, Sichuan 610066, China
| | - Bingyun Xie
- College of Chemistry and Material Science, Sichuan Normal University, Key Laboratory of Advanced Functional Materials, Sichuan Province Higher Education System, Chengdu, Sichuan 610066, China
| | - Quan Li
- College of Chemistry and Material Science, Sichuan Normal University, Key Laboratory of Advanced Functional Materials, Sichuan Province Higher Education System, Chengdu, Sichuan 610066, China
| | - Keqing Zhao
- College of Chemistry and Material Science, Sichuan Normal University, Key Laboratory of Advanced Functional Materials, Sichuan Province Higher Education System, Chengdu, Sichuan 610066, China
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56
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Pedone A, Biczysko M, Barone V. Environmental effects in computational spectroscopy: accuracy and interpretation. Chemphyschem 2010; 11:1812-32. [PMID: 20358575 DOI: 10.1002/cphc.200900976] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Spectroscopic techniques are valuable tools for understanding the structure and dynamics of complex systems, such as biomolecules or nanomaterials. Most of the current research is devoted to the development of new experimental techniques for improving the intrinsic resolution of different spectra. However, the subtle interplay of several different effects acting at different length and time scales still makes the interpretation and analysis of such spectra a very difficult task. In this respect, computational spectroscopy is becoming a needful and versatile tool for the assignment and interpretation of experimental spectra. It is in fact possible nowadays to model with relatively high accuracy the physical-chemical properties of complex molecules in different environments, and to link spectroscopic evidence directly to the structural and dynamical properties of optically or magnetically active solvated probes. In this Review, significant steps toward the simulation of entire spectra in condensed phases are presented together with some basic aspects of computational spectroscopy, which highlight how intramolecular and intermolecular degrees of freedom influence several spectroscopic parameters.
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Affiliation(s)
- Alfonso Pedone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, Pisa, Italy
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57
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Biczysko M, Panek P, Scalmani G, Bloino J, Barone V. Harmonic and Anharmonic Vibrational Frequency Calculations with the Double-Hybrid B2PLYP Method: Analytic Second Derivatives and Benchmark Studies. J Chem Theory Comput 2010; 6:2115-25. [PMID: 26615939 DOI: 10.1021/ct100212p] [Citation(s) in RCA: 221] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This work aims to provide reliable benchmark data on the accuracy of harmonic and anharmonic vibrational frequencies computed with the B2PLYP double-hybrid density functional method. The exchange-correlation contributions required for the B2PLYP analytical second derivatives are presented here, which allow for the effective calculation of harmonic frequency as well as cubic and semidiagonal quartic force fields. The latter, in turn, are necessary to compute the anharmonic vibrational frequencies with the perturbative approach (VPT2). The quality of harmonic vibrational frequencies computed in conjunction with basis sets of double- to quadruple-ζ quality has been checked against reference data from the F38 benchmark set. Then, for an additional set of small closed- and open-shell systems, both harmonic frequencies and anharmonic contributions computed at the B2PLYP/N07D and the B2PLYP/aug-cc-pVTZ levels have been compared to their CCSD(T) counterparts. Moreover, for selected medium-size molecules (furan, pyrrole, thiophene, uracil, anisole, phenol, and pyridine), anharmonic frequencies have been compared to well established experimental results. Such benchmark studies have shown that the B2PLYP/N07D model provides good quality harmonic frequencies and describes correctly anharmonic contributions, the latter being of similar accuracy to their B3LYP/N07D counterparts, but obtained at significantly larger computational cost. Additionally, increased accuracy can be obtained by adopting hybrid models where the B2PLYP/N07D anharmonic contributions are combined with harmonic frequencies computed with more accurate quantum mechanical (QM) approaches or by B2PLYP with larger basis sets. This work confirmed also that most of the recently developed density functionals are significantly less suited for vibrational computations, while the B2PLYP method can be recommended for spectroscopic studies where a good accuracy of vibrational properties is required.
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Affiliation(s)
- Malgorzata Biczysko
- Scuola Normale Superiore, piazza dei Cavalieri 7, 56126 Pisa, Italy, Dipartimento di Chimica "Paolo Corradini" and CR-INSTM Village Università di Napoli Federico II, Complesso Univ. Monte S. Angelo, via Cintia, 80126 Napoli, Italy, Faculty of Chemistry, University of Wroclaw, ul. Joliot-Curie 14, 50-383 Wroclaw, Poland, Gaussian, Inc., 340 Quinnipiac St., Bldg 40, Wallingford, Connecticut 06492, and Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Pisa, Pisa, Italy
| | - Pawel Panek
- Scuola Normale Superiore, piazza dei Cavalieri 7, 56126 Pisa, Italy, Dipartimento di Chimica "Paolo Corradini" and CR-INSTM Village Università di Napoli Federico II, Complesso Univ. Monte S. Angelo, via Cintia, 80126 Napoli, Italy, Faculty of Chemistry, University of Wroclaw, ul. Joliot-Curie 14, 50-383 Wroclaw, Poland, Gaussian, Inc., 340 Quinnipiac St., Bldg 40, Wallingford, Connecticut 06492, and Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Pisa, Pisa, Italy
| | - Giovanni Scalmani
- Scuola Normale Superiore, piazza dei Cavalieri 7, 56126 Pisa, Italy, Dipartimento di Chimica "Paolo Corradini" and CR-INSTM Village Università di Napoli Federico II, Complesso Univ. Monte S. Angelo, via Cintia, 80126 Napoli, Italy, Faculty of Chemistry, University of Wroclaw, ul. Joliot-Curie 14, 50-383 Wroclaw, Poland, Gaussian, Inc., 340 Quinnipiac St., Bldg 40, Wallingford, Connecticut 06492, and Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Pisa, Pisa, Italy
| | - Julien Bloino
- Scuola Normale Superiore, piazza dei Cavalieri 7, 56126 Pisa, Italy, Dipartimento di Chimica "Paolo Corradini" and CR-INSTM Village Università di Napoli Federico II, Complesso Univ. Monte S. Angelo, via Cintia, 80126 Napoli, Italy, Faculty of Chemistry, University of Wroclaw, ul. Joliot-Curie 14, 50-383 Wroclaw, Poland, Gaussian, Inc., 340 Quinnipiac St., Bldg 40, Wallingford, Connecticut 06492, and Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Pisa, Pisa, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, piazza dei Cavalieri 7, 56126 Pisa, Italy, Dipartimento di Chimica "Paolo Corradini" and CR-INSTM Village Università di Napoli Federico II, Complesso Univ. Monte S. Angelo, via Cintia, 80126 Napoli, Italy, Faculty of Chemistry, University of Wroclaw, ul. Joliot-Curie 14, 50-383 Wroclaw, Poland, Gaussian, Inc., 340 Quinnipiac St., Bldg 40, Wallingford, Connecticut 06492, and Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Pisa, Pisa, Italy
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58
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Puzzarini C, Biczysko M, Barone V. Accurate Harmonic/Anharmonic Vibrational Frequencies for Open-Shell Systems: Performances of the B3LYP/N07D Model for Semirigid Free Radicals Benchmarked by CCSD(T) Computations. J Chem Theory Comput 2010; 6:828-38. [DOI: 10.1021/ct900594h] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Cristina Puzzarini
- Dipartimento di Chimica “G. Ciamician”, Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy, Dipartimento di Chimica “Paolo Corradini” and CR-INSTM Village, Università di Napoli Federico II, Complesso Univ. Monte S. Angelo, via Cintia, 80126 Napoli, Italy, and Scuola Normale Superiore, piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Malgorzata Biczysko
- Dipartimento di Chimica “G. Ciamician”, Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy, Dipartimento di Chimica “Paolo Corradini” and CR-INSTM Village, Università di Napoli Federico II, Complesso Univ. Monte S. Angelo, via Cintia, 80126 Napoli, Italy, and Scuola Normale Superiore, piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Vincenzo Barone
- Dipartimento di Chimica “G. Ciamician”, Università di Bologna, Via F. Selmi 2, 40126 Bologna, Italy, Dipartimento di Chimica “Paolo Corradini” and CR-INSTM Village, Università di Napoli Federico II, Complesso Univ. Monte S. Angelo, via Cintia, 80126 Napoli, Italy, and Scuola Normale Superiore, piazza dei Cavalieri 7, 56126 Pisa, Italy
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59
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Barone V, Bloino J, Biczysko M. Validation of the DFT/N07D computational model on the magnetic, vibrational and electronic properties of vinyl radical. Phys Chem Chem Phys 2010; 12:1092-101. [DOI: 10.1039/b915246f] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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60
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Hydrogen bonding in the urea dimers and adenine–thymine DNA base pair: anharmonic effects in the intermolecular H-bond and intramolecular H-stretching vibrations. Theor Chem Acc 2009. [DOI: 10.1007/s00214-009-0645-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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61
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Li Q, Zhao K. Density Functional Theory Study of Hydrogen Bonds of Bipyridine with 1,3,5-Benzenetricarboxylic Acid. CHINESE J CHEM 2009. [DOI: 10.1002/cjoc.200990279] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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62
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Andrushchenko V, Matějka P, Anderson DT, Kaminský J, Horníček J, Paulson LO, Bouř P. Solvent Dependence of the N-Methylacetamide Structure and Force Field. J Phys Chem A 2009; 113:9727-36. [DOI: 10.1021/jp9045512] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Valery Andrushchenko
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences,
Flemingovo nám. 2, 16610, Praha 6, Czech Republic, Department
of Analytical Chemistry, Institute of Chemical Technology, Technická
5, 166 28, Prague 6, Czech Republic, and Department of Chemistry,
University of Wyoming, 1000 East University Avenue, Laramie, Wyoming
82071
| | - Pavel Matějka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences,
Flemingovo nám. 2, 16610, Praha 6, Czech Republic, Department
of Analytical Chemistry, Institute of Chemical Technology, Technická
5, 166 28, Prague 6, Czech Republic, and Department of Chemistry,
University of Wyoming, 1000 East University Avenue, Laramie, Wyoming
82071
| | - David T. Anderson
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences,
Flemingovo nám. 2, 16610, Praha 6, Czech Republic, Department
of Analytical Chemistry, Institute of Chemical Technology, Technická
5, 166 28, Prague 6, Czech Republic, and Department of Chemistry,
University of Wyoming, 1000 East University Avenue, Laramie, Wyoming
82071
| | - Jakub Kaminský
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences,
Flemingovo nám. 2, 16610, Praha 6, Czech Republic, Department
of Analytical Chemistry, Institute of Chemical Technology, Technická
5, 166 28, Prague 6, Czech Republic, and Department of Chemistry,
University of Wyoming, 1000 East University Avenue, Laramie, Wyoming
82071
| | - Jan Horníček
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences,
Flemingovo nám. 2, 16610, Praha 6, Czech Republic, Department
of Analytical Chemistry, Institute of Chemical Technology, Technická
5, 166 28, Prague 6, Czech Republic, and Department of Chemistry,
University of Wyoming, 1000 East University Avenue, Laramie, Wyoming
82071
| | - Leif O. Paulson
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences,
Flemingovo nám. 2, 16610, Praha 6, Czech Republic, Department
of Analytical Chemistry, Institute of Chemical Technology, Technická
5, 166 28, Prague 6, Czech Republic, and Department of Chemistry,
University of Wyoming, 1000 East University Avenue, Laramie, Wyoming
82071
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences,
Flemingovo nám. 2, 16610, Praha 6, Czech Republic, Department
of Analytical Chemistry, Institute of Chemical Technology, Technická
5, 166 28, Prague 6, Czech Republic, and Department of Chemistry,
University of Wyoming, 1000 East University Avenue, Laramie, Wyoming
82071
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63
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Biczysko M, Panek P, Barone V. Toward spectroscopic studies of biologically relevant systems: Vibrational spectrum of adenine as a test case for performances of long-range/dispersion corrected density functionals. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.05.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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64
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Bouteiller Y, Poully JC, Desfrançois C, Grégoire G. Evaluation of MP2, DFT, and DFT-D Methods for the Prediction of Infrared Spectra of Peptides. J Phys Chem A 2009; 113:6301-7. [DOI: 10.1021/jp901570r] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Yves Bouteiller
- Laboratoire de Physique des Lasers, CNRS, UMR 7538, Institut Galilée, Université Paris 13, 93430, Villetaneuse, France
| | - Jean Christophe Poully
- Laboratoire de Physique des Lasers, CNRS, UMR 7538, Institut Galilée, Université Paris 13, 93430, Villetaneuse, France
| | - Charles Desfrançois
- Laboratoire de Physique des Lasers, CNRS, UMR 7538, Institut Galilée, Université Paris 13, 93430, Villetaneuse, France
| | - Gilles Grégoire
- Laboratoire de Physique des Lasers, CNRS, UMR 7538, Institut Galilée, Université Paris 13, 93430, Villetaneuse, France
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65
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Cané E, Trombetti A. The anharmonic force field of 1,3-cyclopentadienes. Phys Chem Chem Phys 2009; 11:2428-32. [PMID: 19325975 DOI: 10.1039/b820716j] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The cubic and quartic semi-diagonal anharmonic force fields of 1,3-cyclopentadienes, C(5)H(6) and C(5)D(6), of the 1,3-cyclopentadiene-5-d and 1,3-cyclopentadiene-1,2,3,4,5-d(5) have been obtained using density functional theory, DFT, with the B97-1 functional and a triple-zeta plus double polarization (TZ2P) basis set. The 108 fundamental frequencies computed by second order vibrational perturbation theory are in very good agreement with the experimental data, with a root mean square deviation (RMSD) equal to 7 cm(-1). Some fundamental frequencies have been reassigned and two have been assigned for the first time on the basis of the present results. The RMSD value, identical to that obtained for naphthalene (E. Cané, A. Miani and A. Trombetti, J. Phys. Chem. A, 2007, 111, 8218), indicates that computations based on this method can be confidently extended to larger polycyclic aromatic hydrocarbons.
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Affiliation(s)
- Elisabetta Cané
- Dipartimento di Chimica Fisica e Inorganica, Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
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66
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Hou Y, Woo HK, Wang P, Xing X, Ng CY, Lau KC. Vacuum ultraviolet pulsed field ionization-photoelectron and infrared-photoinduced Rydberg ionization study of trans-1,3-butadiene. J Chem Phys 2008; 129:114305. [DOI: 10.1063/1.2973635] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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67
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Krasnoshchekov SV, Stepanov NF. Anharmonic Force Fields and Perturbation Theory in the Interpretation of Vibrational Spectra of Polyatomic Molecules. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2008. [DOI: 10.1134/s0036024408040158] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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68
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LI Q, CAI J, CHEN JR, ZHAO KQ. Density Functional Theory Study of Red-shifted Hydrogen Bonds of 4-Pyridinemethanol with Water. CHINESE J CHEM 2008. [DOI: 10.1002/cjoc.200890050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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69
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Kapitán J, Hecht L, Bouř P. Raman spectral evidence of methyl rotation in liquid toluene. Phys Chem Chem Phys 2008; 10:1003-8. [DOI: 10.1039/b713965a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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70
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Levi C, Martin JML, Bar I. Fundamental vibrational frequencies and dominant resonances in methylamine isotopologues byab initio and density functional theory methods. J Comput Chem 2008; 29:1268-76. [DOI: 10.1002/jcc.20885] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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71
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Cané E, Miani A, Trombetti A. Anharmonic Force Fields of Naphthalene-h8and Naphthalene-d8. J Phys Chem A 2007; 111:8218-22. [PMID: 17672437 DOI: 10.1021/jp071610p] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cubic and the quartic semidiagonal anharmonic force fields of naphthalene-h8 and -d8 are obtained using density functional theory (DFT) with the B9-71 functional and a triple-zeta plus double polarization (TZ2P) basis set. The fundamental frequencies computed by second-order vibrational perturbation theory are in very good agreement with the experimental data, with a mean absolute deviation (MAD) of 4 cm(-1) for C(10)H(8) and 6 cm(-1) for C(10)D(8). Some of the fundamental frequencies have been reassigned on the basis of the present results. Only CH stretchings seem to be significantly affected by Fermi resonances, with two shifts larger than 10 cm(-1). Calculated infrared harmonic intensities reproduce the experimental data within 15%, with the exception of CH stretchings affected by a larger error. Scale factors from C(10)H(8) have been tested by deriving the fundamental frequencies of C(10)D(8) from the theoretical harmonic ones. These fundamentals are in nice agreement with those obtained from the C(10)D(8) anharmonic force field. These results support the use of scale factors to calculate the vibration spectra of larger polycyclic aromatic hydrocarbons of great astrophysical interest.
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Affiliation(s)
- Elisabetta Cané
- Dipartimento di Chimica Fisica e Inorganica, Facoltà di Chimica Industriale, Università di Bologna, Viale Risorgimento 4, 40136 Bologna, Italy
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72
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Abstract
The principal contributions to the anharmonic coupling of amide vibrations are explored with the objective of comparing recent experiments with density functional theory and evaluating simple models of mode coupling. Experimental information obtained by means of two-dimensional infrared spectroscopy (2D IR) is reasonably well predicted by the computed one- and two-quantum anharmonic modes of amide-A, -I, and -II types in mono-, di- and tripeptides. The expansion of the vibrational energy up to the cubic and quartic coupling of harmonic modes suggested criteria to assess how localized are the forces determining the anharmonicity. The off-diagonal anharmonicity between an amide-A and one other amide mode was shown to be mainly determined by forces involving only these two modes, whereas the off-diagonal anharmonicity of two amide-I modes in peptides depended significantly on forces due to motions other than those of the amide-I type. Both the diagonal and off-diagonal anharmonicities exhibit sensitivity to peptide structures. These results should prove useful in linking 2D IR experimental results to secondary structure. Further, the results are used to evaluate the vibrational exciton model for the mixed-mode anharmonicities of the amide-I transitions.
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Affiliation(s)
- Jianping Wang
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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73
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Gupta VP. Anharmonic analysis of the vibrational spectrum of ketene by density functional theory using second-order perturbative approach. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2007; 67:870-6. [PMID: 17049910 DOI: 10.1016/j.saa.2006.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Revised: 08/24/2006] [Accepted: 09/01/2006] [Indexed: 05/12/2023]
Abstract
The paper reports main results of a comprehensive study of the vibrational spectrum of ketene computed using second-order perturbation theory treatment based on quartic, cubic and semidiagonal quartic force constants. Two different models--a homogeneous model using the same density functionals and basis functions for the harmonic calculations and anharmonic corrections, and a hybrid model in which the two parts of the calculation are conducted using different density functionals and basis sets--have been employed in the present calculations. Different DFT and CCSD methods and DZ and TZ extended basis sets involving diffuse and polarization functions have been used to calculate optimized and vibrationally averaged geometrical parameters, the harmonic and anharmonic vibrational frequencies and the spectroscopic constants such as anharmonicity constants, rotational constants, rotation-vibration coupling constants, Nielsen's centrifugal distortion constants and Coriolis coupling constants. Homogeneous model is found to be superior to the hybrid model in several respects. Difficulties in the hybrid model may arise due to one of the following reasons: (a) the basic requirement that the geometry optimization and frequency calculations must be done at the same level of theory to have valid frequencies is not met in the hybrid model; (b) the molecular structure gets reoptimized at the low level for anharmonic corrections; (c) in addition, the perturbation could also diverge for the above reasons, particularly for the very low, very anharmonic terms where the harmonic approximation is not close enough to make the perturbation work.
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Affiliation(s)
- V P Gupta
- Department of Physics, University of Jammu, Jammu-Tawi 180006, India.
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74
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Albert S, Quack M. High Resolution Rovibrational Spectroscopy of Chiral and Aromatic Compounds. Chemphyschem 2007; 8:1271-81. [PMID: 17566970 DOI: 10.1002/cphc.200700018] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The analysis of selected rovibrationally resolved infrared spectra of some relatively heavy and large polyatomic molecules is reviewed. A short historical summary of the development of high resolution interferometric Fourier transform infrared (FTIR) spectrometers is given and the possibilities of the currently most highly resolving FTIR spectrometer, which is commercially available in the Bruker IFS 125 series, are discussed. The computational tools necessary to analyse FTIR spectra are described briefly. As examples of rovibrational analysis the spectra of three selected molecules CHCl(2)F, CDBrClF, and pyridine (C(5)H(5)N) are discussed. The spectrum of CHCl(2)F, a fluorochlorohydrocarbon, is of interest for a better understanding of the chemistry of the Earth's atmosphere. CDBrClF is a chiral molecule and therefore the analysis of its rovibrational spectra provides the basis for carrying out further experiments towards the detection of molecular parity violation. The analysis of the pyridine FTIR spectra illustrates the potential of the new generation of FTIR spectrometers in the study of spectra and rovibrational dynamics of aromatic systems and molecules of potential biological interest.
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Affiliation(s)
- Sieghard Albert
- Laboratorium für Physikalische Chemie, ETH Zürich, Wolfgang Pauli Str. 10, 8093 Zürich, Switzerland.
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75
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Barone V, Cimino P, Crescenzi O, Pavone M. Ab initio computation of spectroscopic parameters as a tool for the structural elucidation of organic systems. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.theochem.2006.12.056] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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76
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Centeno S, López-Tocón I, Arenas J, Otero J. Assignment of the vibrational spectrum of trimethylpyrazine. J Mol Struct 2007. [DOI: 10.1016/j.molstruc.2006.11.060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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77
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Makarewicz J. Structure and Dynamics of the Aniline−Argon Complex as Derived from its Potential Energy Surface. J Phys Chem A 2007; 111:1498-507. [PMID: 17279733 DOI: 10.1021/jp0654866] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The structure and dynamics of the van der Waals (vdW) complex of aniline (An) with argon (Ar) are studied using ab initio methods. The inversion potential of the aniline-argon (AnAr) complex perturbed by the weak vdW interaction is calculated taking into account subtle corrections from the zero-point energy of the vdW modes and from the frequency shifts of the An normal modes modified by the complexation. The intermolecular potential energy surface (PES) of the AnAr complex is determined by performing a large-scale computation of the interaction energy and the fitting of the analytical many-body expansion to the set of single-point interaction energies. The PES determined shows two deep local minima corresponding to the anti and syn AnAr conformers. The difference in the energies of these two minima is only 15 cm-1, but it is sufficient to localize the inversion wave functions and to form the two conformers. In the conformer anti (syn) of lower (higher) energy, Ar is bound to the An ring opposite (adjacent) the amino-hydrogens. In the additional local minima higher in energy, Ar approaches the aniline ring between the C-H bonds near its plane. An additional local minimum is located opposite of nitrogen between the two N-H bonds. The high-energy minima are, however, too flat to form stable conformers. The perturbation of the interaction of Ar with the phenyl ring by the NH2 group is described by the vdW hole, which is responsible for unusually strong intermode mixing in the excited intermolecular vibrational states. The analysis of these states calculated for the ground (S0) as well as the first excited electronic state (S1) resolves difficulties faced earlier with the assignment of the observed vibronic bands of AnAr.
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Affiliation(s)
- Jan Makarewicz
- Faculty of Chemistry, A. Mickiewicz University, Grunwaldzka 6, PL 60-780 Poznań, Poland.
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78
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Aree T, Bürgi HB. Specific heat of molecular crystals from atomic mean square displacements with the Einstein, Debye, and Nernst-Lindemann models. J Phys Chem B 2007; 110:26129-34. [PMID: 17181267 DOI: 10.1021/jp0636322] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Analysis of atomic displacement parameters (ADPs) from multitemperature diffraction data provides mean-field molecular translation and libration frequencies. These quantities have been combined with molecular deformation frequencies calculated ab initio, e.g. by DFT methods, to calculate the specific heat Cv of molecular crystals of naphthalene, anthracene, and hexamethylenetetramine. If the difference Cp - Cv is represented by the Nernst-Lindemann relation, Cp curves from diffraction experiments and ab initio calculations agree well with those based on calorimetry. Agreement is better if the Debye rather than the Einstein model is chosen to represent the contribution of the translational vibrations. Compressibilities estimated from the differences Cp - Cv are 2-5 times higher than those obtained from compressibility measurements at 298 K and Grüneisen constants derived from the temperature dependence of ADPs.
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Affiliation(s)
- Thammarat Aree
- Laboratorium für Chemische und Mineralogische Kristallographie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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79
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Theoretical modeling of spectroscopic properties of molecules in solution: toward an effective dynamical discrete/continuum approach. Theor Chem Acc 2007. [DOI: 10.1007/s00214-006-0216-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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80
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Alía JM, Edwards HGM, Fawcett WR, Smagala TG. An Experimental Raman and Theoretical DFT Study on the Self-Association of Acrylonitrile. J Phys Chem A 2007; 111:793-804. [PMID: 17266219 DOI: 10.1021/jp0663210] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The liquid structure of acrylonitrile (propenenitrile) has been investigated using Raman spectroscopy and density functional theory (DFT) ab initio calculations with the 6-311++G** basis set. Two different and complementary experimental approaches were undertaken: FT-Raman spectra of 13 acrylonitrile solutions in carbon tetrachloride (concentration range=0.25-12.0 mol.L-1) were studied in detail including principal component analysis (PCA) of the CN stretching band. Furthermore, dispersive Raman spectra of neat acrylonitrile were obtained at eight different temperatures from 238 up to 343 K. The complex and asymmetric acrylonitrile Raman CN stretching band can be decomposed into two components attributed to monomeric and self-associated forms. Ab initio results fully support this assignment and suggest that the self-associated complex is a nonplanar trimer held together by dipole-dipole interactions. At ambient temperature, the composition of acrylonitrile can be expressed as a mixture of 25% monomers and 75% trimers. Close to the boiling point, trimers still represent 65% of the liquid composition. The corresponding enthalpy of association was estimated to be -22+/-2 kJ.mol-1.
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Affiliation(s)
- Jose M Alía
- Department of Chemistry, University of California, Davis, California 95616, USA.
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81
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Barone V. Anharmonic vibrational properties by a fully automated second-order perturbative approach. J Chem Phys 2007; 122:14108. [PMID: 15638643 DOI: 10.1063/1.1824881] [Citation(s) in RCA: 1142] [Impact Index Per Article: 67.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This paper describes the implementation of a fully automated code for the building of anharmonic force constants and their use in a second-order perturbative evaluation of vibrorotational parameters. Next, a number of test applications are discussed, which show the strengths and limits of various computational levels.
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Affiliation(s)
- Vincenzo Barone
- Laboratorio di Struttura e Dinamica Molecolare, Dipartimento di Chimica, Università Federico II, Complesso Universitario Monte Sant'Angelo, Via Cintia, I-80126 Naples, Italy.
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82
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Danecek P, Bour P. Comparison of the numerical stability of methods for anharmonic calculations of vibrational molecular energies. J Comput Chem 2007; 28:1617-24. [PMID: 17340607 DOI: 10.1002/jcc.20654] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
On model examples, we compare the performance of the vibrational self-consistent field, variational, and four perturbational schemes used for computations of vibrational energies of semi-rigid molecules, with emphasis on the numerical stability. Although the accuracy of the energies is primarily dependent on the quality of the potential energy surface, approximate approaches to the anharmonic vibrational problem often do not converge to the same results due to the approximations involved. For furan, the sensitivity to variations of the anharmonic potential was systematically investigated by adding random noise to the cubic and quartic constants. The self-consistent field methods proved to be the most resistant to the potential variations. The second order perturbational techniques are sensitive to random degeneracies and provided the least stable results. However, their stability could be significantly improved by a simple generalization of the perturbational formula. The variational configuration interaction is practically limited by the size of the matrix that can be diagonalized for larger molecules; however, relatively fewer states need to be involved than for smaller ones, in favor of the computing.
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Affiliation(s)
- Petr Danecek
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague, Czech Republic
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83
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Christiansen O. Vibrational structure theory: new vibrational wave function methods for calculation of anharmonic vibrational energies and vibrational contributions to molecular properties. Phys Chem Chem Phys 2007; 9:2942-53. [PMID: 17551617 DOI: 10.1039/b618764a] [Citation(s) in RCA: 190] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A number of recently developed theoretical methods for the calculation of vibrational energies and wave functions are reviewed. Methods for constructing the appropriate quantum mechanical Hamilton operator are briefly described before reviewing a particular branch of theoretical methods for solving the nuclear Schrödinger equation. The main focus is on wave function methods using the vibrational self-consistent field (VSCF) as starting point, and includes vibrational configuration interaction (VCI), vibrational Møller-Plesset (VMP) theory, and vibrational coupled cluster (VCC) theory. The convergence of the different methods towards the full vibrational configuration interaction (FVCI) result is discussed. Finally, newly developed vibrational response methods for calculation of vibrational contributions to properties, energies, and transition probabilities are discussed.
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Affiliation(s)
- Ove Christiansen
- The Lundbeck Foundation Center for Theoretical Chemistry, Department of Chemistry, Aarhus University, DK-8000 Arhus C, Denmark
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84
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Frey JA, Leist R, Tanner C, Frey HM, Leutwyler S. 2-pyridone: The role of out-of-plane vibrations on the S1↔S0 spectra and S1 state reactivity. J Chem Phys 2006; 125:114308. [PMID: 16999475 DOI: 10.1063/1.2338042] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The S(1)<-->S(0) vibronic spectra of supersonic jet-cooled 2-pyridone [pyridin-2-one (2PY)] and its N-H deuterated isotopomer (d-2PY) have been recorded by two-color resonant two-photon ionization, laser-induced fluorescence and emission, and fluorescence depletion spectroscopies. By combining these methods, the B origin of 2PY at 0(0) (0)+98 cm(-1) and the bands at +218 and +252 cm(-1) are identified as overtones of the S(1) state out-of-plane vibrations nu(1) (') and nu(2) ('), as are the analogous bands of d-2PY. Anharmonic double-minimum potentials are derived for the respective out-of-plane coordinates that predict further nu(1) (') and nu(2) (') overtones and combinations, reproducing approximately 80% of the vibronic bands up to 600 cm(-1) above the 0(0) (0) band. The fluorescence spectra excited at the electronic origins and the nu(1) (') and nu(2) (') out-of-plane overtone levels confirm these assignments. The S(1) nonplanar minima and S(1)<--S(0) out-of-plane progressions are in agreement with the determination of nonplanar vibrationally averaged geometries for the 0(0) (0) and 0(0) (0)+98 cm(-1) upper states by Held et al. [J. Chem. Phys. 95, 8732 (1991)]. The fluorescence lifetimes of the S(1) state vibrations show strong mode dependence: Those of the out-of-plane levels decrease rapidly above 200 cm(-1) excess vibrational energy, while the in-plane vibrations nu(5) ('), nu(8) ('), and nu(9) (') have longer lifetimes, although they are above or interspersed with the "dark" out-of-plane states. This is interpreted in terms of an S(1) (') state reaction with a low barrier towards a conical intersection with a prefulvenic geometry. Out-of-plane vibrational states can directly surmount this barrier, whereas in-plane vibrations are much less efficient in this respect. Analysis of the fluorescence spectra allows to identify nine in-plane S(0) (') state fundamentals, overtones of the S(0) state nu(1) (") and nu(2) (") out-of-plane vibrations, and >30 other overtones and combination bands. The B3LYP6-311++G(d,p) calculated anharmonic wave numbers are in very good agreement with the observed fundamentals, overtones, and combinations, with a deviation Delta(rms)=1.3%.
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Affiliation(s)
- Jann A Frey
- Departement für Chemie und Biochemie, Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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85
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86
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Barsberg S, Berg RW. Combined Raman Spectroscopic and Theoretical Investigation of Fundamental Vibrational Bands of Furfuryl Alcohol (2-furanmethanol). J Phys Chem A 2006; 110:9500-4. [PMID: 16869701 DOI: 10.1021/jp061642x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Furfuryl alcohol (FA) is a promising reactive precursor for new materials. FA reaction mechanisms, that is, self-reactions or cross reactions with other substances, can be studied by vibrational spectroscopy. We present a necessary prerequisite for such studies by a Raman spectroscopic and theoretical study of FA in weakly interacting environments. It is the first study of FA vibrational properties based on density functional theory (DFT/B3LYP), and a recently proposed hybrid approach to the calculation of fundamental frequencies, which also includes an anharmonic contribution. FA occupies five different conformational states, each with more than 5% probability, and two of these dominate at T = 298 K. Excluding one frequency, the remaining ones are predicted as a weighted average over the two dominant conformers to a best RMS error of 8 cm(-1) and are qualitatively assigned. The excluded CH stretching mode is underestimated by 65 cm(-1). This may be due to a combination of an insufficient level of theory and the neglect of Fermi interactions for properly describing this type of mode.
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Affiliation(s)
- S Barsberg
- The Royal Veterinary and Agricultural University, Forest and Landscape, Rolighedsvej 23, DK-1958 Frederiksberg C, Denmark.
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87
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C. Lau K, Ng CY. Accurate ab initio Predictions of Ionization Energies and Heats of Formation for Cyclopropenylidene, Propargylene and Propadienylidene. CHINESE J CHEM PHYS 2006. [DOI: 10.1360/cjcp2006.19(1).29.10] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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88
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Dunn ME, Evans TM, Kirschner KN, Shields GC. Prediction of accurate anharmonic experimental vibrational frequencies for water clusters, (H2O)n, n=2-5. J Phys Chem A 2006; 110:303-9. [PMID: 16392869 PMCID: PMC2548414 DOI: 10.1021/jp054958y] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Accurate anharmonic experimental vibrational frequencies for water clusters consisting of 2-5 water molecules have been predicted on the basis of comparing different methods with MP2/aug-cc-pVTZ calculated and experimental anharmonic frequencies. The combination of using HF/6-31G* scaled frequencies for intramolecular modes and anharmonic frequencies for intermolecular modes gives excellent agreement with experiment for the water dimer and trimer and are as good as the expensive anharmonic MP2 calculations. The water trimer, the cyclic Ci and S4 tetramers, and the cyclic pentamer all have unique peaks in the infrared spectrum between 500 and 800 cm-1 and between 3400 and 3700 cm-1. Under the right experimental conditions these different clusters can be uniquely identified using high-resolution IR spectroscopy.
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Affiliation(s)
- Meghan E Dunn
- Department of Chemistry, Hamilton College, 198 College Hill Road, Clinton, New York 13323, USA
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89
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Barone V, Polimeno A. Toward an integrated computational approach to CW-ESR spectra of free radicals. Phys Chem Chem Phys 2006; 8:4609-29. [PMID: 17047758 DOI: 10.1039/b607998a] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Interpretation of structural properties and dynamic behaviour of molecules in solution is of fundamental importance to understand their stability, chemical reactivity and catalytic action. Information can be gained, in principle, by a variety of spectroscopic techniques, magnetic as well as optical. In particular, continuous wave electron spin resonance (CW-ESR) measurements are highly informative. However, the wealth of structural and dynamic information which can be extracted from ESR spectroscopy is, at present, limited by the necessity of employing computationally efficient models, which are increasingly complex as they need to take into account diverse relaxation processes affecting the spectrum. In this paper, we address the basic theoretical tools needed to predict, essentially ab initio, CW-ESR spectra observables according to the stochastic Liouville equation (SLE) approach, combined with quantum mechanical and hybrid methods for the accurate and efficient computation of structural, spectroscopic and magnetic properties of molecular systems. We shall discuss, on one hand, the quantum mechanical calculation of magnetic observables, via density functional theory (DFT), time-dependent DFT (TD-DFT) and application of the polarizable continuum model (PCM) for the description of environmental effects, including anisotropic environments and systems where different regions are characterized by different dielectric constants. One the other hand, the explicit evaluation of dynamical effects will be discussed based on the numerically exact treatment of the SLE in the presence of several relaxation processes, which has been proven to be a challenging task.
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Affiliation(s)
- Vincenzo Barone
- Dipartimento di Chimica, Università di Napoli "Federico II", Complesso Universitario di Monte Sant'Angelo Via Cintia, I-80126, Napoli, Italy
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90
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Boese AD, Martin JM. Anharmonic force fields of perchloric acid, HClO4, and perchloric anhydride, Cl2O7. An extreme case of inner polarization. J Mol Struct 2006. [DOI: 10.1016/j.molstruc.2005.07.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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91
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Barone V, Viglione RG. Harmonic and anharmonic contributions to parity-violating vibrational frequency difference between enantiomers of chiral molecules. J Chem Phys 2005; 123:234304. [PMID: 16392917 DOI: 10.1063/1.2137719] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A general perturbative procedure for the computation of harmonic and anharmonic contributions to parity-violating vibrational shifts is introduced and applied to PHBrF and AsHBrF. The results point out the importance of both diagonal and off-diagonal anharmonic contributions and indicate that some parity-violating shift of AsHBrF approaches the resolution forecasted for next generation experiments. The proposed approach is sufficiently general and computationally effective to allow studies of similar and larger molecular systems.
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Affiliation(s)
- Vincenzo Barone
- Dipartimento di Chimica, Università di Napoli Federico II, via Cintia, 80126 Napoli, Italy.
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92
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Celebre G, De Luca G, Emsley JW, Longeri M, Merlet D, Pileio G, Suryaprakash N. Obtaining the structure and bond rotational potential of a substituted ethane by NMR spectroscopy of solutions in nematic liquid-crystalline solvents. J Chem Phys 2005; 123:194907. [PMID: 16321113 DOI: 10.1063/1.2121628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Partially averaged dipolar couplings (also referred to as residual dipolar couplings) D(ij) can be obtained from the analysis of the NMR spectra of molecules dissolved in liquid-crystalline solvents. Their values for a nonrigid molecule depend upon the bond lengths and angles, the rotational potentials, and the orientational order of the molecules. The molecule studied, 1-chloro-2-bromoethane, is one of the simplest example of a substituted alkane in which the rotational potential has three minimum-energy positions, trans and gauche+/-conformations, and the present investigation explores the problems inherent in deriving the form of the potential and the molecular geometry from the set of partially averaged couplings between the protons, and between protons and (13)C nuclei. The geometrical parameters and the rotational potential obtained are compared with the results from a density-functional theory method.
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Affiliation(s)
- G Celebre
- Department of Chemistry, Universita della Calabria, Arcavacata di Rende, 87036 Rende, Italy
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93
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Concistré M, De Lorenzo L, De Luca G, Longeri M, Pileio G, Raos G. Conformational Analysis of 2,2‘-Bithiophene: A 1H Liquid Crystal NMR Study Using the 13C Satellite Spectra. J Phys Chem A 2005; 109:9953-63. [PMID: 16838912 DOI: 10.1021/jp054003f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have obtained a very large data set of spectral parameters from the analysis of (1)H NMR and (13)C satellite spectra of 2,2'-bithiophene dissolved in anisotropic, partially orienting mesophases. In particular, this parameter set includes 33 dipolar couplings, which are directly related to the interatomic distances, the dihedral angle phi between the two thiophenic rings, and the anisotropic solute-solvent interaction potential. This allows an exhaustive investigation of the conformational equilibrium of 2,2'-bithiophene in a liquidlike phase. Comparison with the predictions of high-level theoretical calculations for the isolated molecule provides evidence of a strong flattening as well as the sharpening effect of the medium on the conformer population. The approximations needed to apply vibrational corrections to flexible molecules are discussed in detail and some general conclusions concerning their effect on structure and conformational equilibria are proposed.
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Affiliation(s)
- Maria Concistré
- Dipartimento di Chimica, Universita della Calabria, Via P. Bucci, 87030 Arcavacata di Rende (Cs), Italy
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94
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Concistrè M, De Luca G, Longeri M, Pileio G, Emsley JW. The Structure and Conformations of 2-Thiophenecarboxaldehyde Obtained from Partially Averaged Dipolar Couplings. Chemphyschem 2005; 6:1483-91. [PMID: 16082671 DOI: 10.1002/cphc.200500190] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The proton NMR spectra of samples of 2-thiophenecarboxaldehyde dissolved in a nematic liquid crystalline solvent, including those from all five singly labelled 13C isotopomers, have been obtained. These have been analysed to yield sets of partially averaged dipolar couplings which have been used to determine the structure and the relative amounts of the cis and trans forms, which are the two minimum-energy structures generated by rotation about the ring-aldehyde bond. A procedure for applying vibrational corrections to the dipolar couplings in the presence of large amplitude motions is discussed.
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Affiliation(s)
- Maria Concistrè
- Dipartimento di Chimica, Università della Calabria, Via P. Bucci, 87030, Arcavacata, Rende (Cs), Italy
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95
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Brauer B, Gerber RB, Kabelác M, Hobza P, Bakker JM, Abo Riziq AG, de Vries MS. Vibrational Spectroscopy of the G· · ·C Base Pair: Experiment, Harmonic and Anharmonic Calculations, and the Nature of the Anharmonic Couplings. J Phys Chem A 2005; 109:6974-84. [PMID: 16834057 DOI: 10.1021/jp051767m] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The results of harmonic and anharmonic frequency calculations on a guanine-cytosine complex with an enolic structure (a tautomeric form with cytosine in the enol form and with a hydrogen at the 7-position on guanine) are presented and compared to gas-phase IR-UV double resonance spectral data. Harmonic frequencies were obtained at the RI-MP2/cc-pVDZ, RI-MP2/TZVPP, and semiempirical PM3 levels of electronic structure theory. Anharmonic frequencies were obtained by the CC-VSCF method with improved PM3 potential surfaces; the improved PM3 potential surfaces are obtained from standard PM3 theory by coordinate scaling such that the improved PM3 harmonic frequencies are the same as those computed at the RI-MP2/cc-pVDZ level. Comparison of the data with experimental results indicates that the average absolute percentage deviation for the methods is 2.6% for harmonic RI-MP2/cc-pVDZ (3.0% with the inclusion of a 0.956 scaling factor that compensates for anharmonicity), 2.5% for harmonic RI-MP2/TZVPP (2.9% with a 0.956 anharmonicity factor included), and 2.3% for adapted PM3 CC-VSCF; the empirical scaling factor for the ab initio harmonic calculations improves the stretching frequencies but decreases the accuracy of the other mode frequencies. The agreement with experiment supports the adequacy of the improved PM3 potentials for describing the anharmonic force field of the G...C base pair in the spectroscopically probed region. These results may be useful for the prediction of the pathways of vibrational energy flow upon excitation of this system. The anharmonic calculations indicate that anharmonicity along single mode coordinates can be significant for simple stretching modes. For several other cases, coupling between different vibrational modes provides the main contribution to anharmonicity. Examples of strongly anharmonically coupled modes are the symmetric stretch and group torsion of the hydrogen-bonded NH2 group on guanine, the OH stretch and torsion of the enol group on cytosine, and the NH stretch and NH out-of-plane bend of the non-hydrogen-bonded NH group on guanine.
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Affiliation(s)
- Brina Brauer
- Department of Physical Chemistry and Fritz Haber Research Center, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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96
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Kassab E, Castellà-Ventura M. Theoretical Study of Pyridine and 4,4‘-Bipyridine Adsorption on the Lewis Acid Sites of Alumina Surfaces Based on Ab Initio and Density Functional Cluster Calculations. J Phys Chem B 2005; 109:13716-28. [PMID: 16852719 DOI: 10.1021/jp040524b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The interactions of pyridine and 4,4'-bipyridine with the Lewis acid sites of alumina surfaces are investigated using ab initio and density functional calculations. Four cluster models of different sizes and shapes are chosen to represent the Lewis acid sites: three hydrogenated clusters Al(OH)(3), Al(4)O(9)H(6), and Al(10)O(21)H(12) and one non-hydrogenated cluster Al(4)O(6). The Hartree-Fock (HF) and B3LYP approaches with two basis sets 6-31G and 6-31+G are used to calculate the geometries, the electronic structures, the vibrational frequencies, and the adsorption energies of the complexes formed upon interaction of pyridine or 4,4'-bipyridine ligands on the cluster surfaces. Electronic structures are determined by the electrostatic potential (ESP) analysis of charges. Adsorption energies are calculated with corrections made for zero-point energies (ZPE) and basis set superposition error (BSSE). The ESP analysis of atomic charges reveals that the charge-transfer effects are more important in Lewis complexes formed with Al(4)O(6) cluster than in those formed with hydrogenated clusters Al(OH)(3), Al(4)O(9)H(6), and Al(10)O(21)H(12). The significantly larger charge transferred from pyridine or 4,4'-bipyridine ligand to Al(4)O(6) cluster should increase the adsorption energy of these complexes. Consequently, at all levels of calculation, the adsorption energies of pyridine and 4,4'-bipyridine complexed to Al(4)O(6) cluster ( approximately 46 kcal/mol), which compare very well to experiment, are strongly larger than those obtained for both pyridine and 4,4'-bipyridine ligands complexed to Al(OH)(3) (32 kcal/mol), Al(4)O(9)H(6) (24 kcal/mol) and Al(10)O(21)H(12) (25 kcal/mol) clusters. The corrected adsorption energy is found to be insensitive to basis set and electron correlation effects. It essentially depends on the ionic character of the cluster model rather than on its size. For 4,4'-bipyridine complexes, similar results to those obtained for pyridine are found, and the geometry and the amount of charge of the unbound pyridyl ring are unchanged upon complexation. The calculated vibrational frequencies and frequency shifts are little sensitive to the size and shape of the cluster model. The two ring stretching modes 8a and 19b of pyridine and 4,4'-bipyridine observed in the 1400-1600 cm(-1) region are the most affected modes upon adsorption, in good agreement with the available infrared and Raman data.
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Affiliation(s)
- Emile Kassab
- Laboratoire de Chimie Théorique, CNRS-UMR 7616, Université Pierre et Marie Curie, Tour 22-23, Case 137, 4 place Jussieu, 75252 Paris Cedex 05, France.
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97
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Lau KC, Ng CY. Accurate ab initio predictions of ionization energies of hydrocarbon radicals: CH2, CH3, C2H, C2H3, C2H5, C3H3, and C3H5. J Chem Phys 2005; 122:224310. [PMID: 15974671 DOI: 10.1063/1.1926274] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ionization energies for methylene (CH2), methyl (CH3), ethynyl (C2H), vinyl (C2H3), ethyl (C2H5), propargyl (C3H3), and allyl (C3H5) radicals have been calculated by the wave-function-based ab initio CCSD(T)/CBS approach, which involves the approximation to the complete basis set (CBS) limit at the coupled-cluster level with single and double excitations plus a quasiperturbative triple excitation [CCSD(T)]. When it is appropriate, the zero-point vibrational energy correction, the core-valence electronic correction, the scalar relativistic effect correction, the diagonal Born-Oppenheimer correction, and the high-order correlation correction have also been made in these calculations. The comparison between the computed ionization energy (IE) values and the highly precise experimental IE values determined in previous pulsed field ionization-photoelectron (PFI-PE) studies indicates that the CCSD(T)/CBS method is capable of providing accurate IE predictions for these hydrocarbon radicals achieving error limits well within +/-10 meV. The benchmarking of the CCSD(T)/CBS IE predictions by the PFI-PE experimental results also lends strong support for the conclusion that the CCSD(T)/CBS approach with high-level energy corrections can serve as a valuable alternative for reliable IE determination of radicals, particularly for those radicals with very unfavorable Franck-Condon factors for photoionization transitions near their ionization thresholds.
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Affiliation(s)
- K-C Lau
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
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98
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Barone V, Carbonniere P, Pouchan C. Accurate vibrational spectra and magnetic properties of organic free radicals: The case of H2CN. J Chem Phys 2005; 122:224308. [PMID: 15974669 DOI: 10.1063/1.1924592] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present the structural, magnetic, and vibrational properties of H2CN computed using a second-order perturbative approach in which equilibrium values and harmonic frequencies evaluated at the coupled-cluster level are combined with anharmonic and vibrational averaging contributions obtained by hybrid Hartree-Fock/Kohn-Sham methods. Our computations lead to remarkably accurate results and suggest some revision of the experimental vibrational assignments.
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Affiliation(s)
- Vincenzo Barone
- Dipartimento di Chimica, Università Federico II, Complesso Monte S. Angelo, via Cintia, 1-80126 Napoli, Italy.
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99
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Daniel Boese A, Klopper W, Martin * JML. Anharmonic force fields and thermodynamic functions using density functional theory. Mol Phys 2005. [DOI: 10.1080/00268970512331339369] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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100
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Carbonniere P, Lucca T, Pouchan C, Rega N, Barone V. Vibrational computations beyond the harmonic approximation: Performances of the B3LYP density functional for semirigid molecules. J Comput Chem 2005; 26:384-8. [PMID: 15651031 DOI: 10.1002/jcc.20170] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The performances of the B3LYP density functional in the computation of harmonic and anharmonic frequencies were tested using 14 standard basis sets of double and triple zeta quality for a set of semirigid molecules containing from 4 to 12 atoms. The quality of the results is assessed by comparison with the most reliable computations available in the literature. The study reveals that the relatively cheap 6-31+G(d,p) basis set performs a very good job for harmonic frequency calculations and that B3LYP anharmonicities are in close agreement with the reference values irrespective of the basis set used. On these grounds "hybrid force fields" are proposed to achieve the best compromise between computer time and quality of the results.
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Affiliation(s)
- Philippe Carbonniere
- Dipartimento di Chimica, Università Federico II, Complesso Universitario Monte Sant'Angelo, Via Cintia, I-80126 Napoli, Italy
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