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Harmonic vibrational frequencies: Scale factors for pure, hybrid, hybrid meta, and double‐hybrid functionals in conjunction with correlation consistent basis sets
Author(s) -
Laury Marie L.,
Boesch Scott E.,
Haken Ian,
Sinha Pankaj,
Wheeler Ralph A.,
Wilson Angela K.
Publication year - 2011
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.21811
Subject(s) - scaling , zero point energy , basis set , basis (linear algebra) , chemistry , hybrid functional , harmonic , molecular vibration , enthalpy , molecule , thermodynamics , zero (linguistics) , atomic physics , physics , molecular physics , computational chemistry , quantum mechanics , mathematics , density functional theory , geometry , linguistics , philosophy
Abstract Scale factors for (a) low (<1000 cm −1 ) and high harmonic vibrational frequencies, (b) thermal contributions to enthalpy and entropy, and (c) zero‐point vibrational energies have been determined for five hybrid functionals (B3P86, B3PW91, PBE1PBE, BH&HLYP, MPW1K), five pure functionals (BLYP, BPW91, PBEPBE, HCTH93, and BP86), four hybrid meta functionals (M05, M05‐2X, M06, and M06‐2X) and one double‐hybrid functional (B2GP‐PLYP) in combination with the correlation consistent basis sets [cc‐pVnZ and aug‐cc‐pVnZ, n = D(2),T(3),Q(4)]. Calculations for vibrational frequencies were carried out on 41 organic molecules and an additional set of 22 small molecules was used for the zero‐point vibrational energy scale factors. Before scaling, approximately 25% of the calculated frequencies were within 3% of experimental frequencies. Upon application of the derived scale factors, nearly 90% of the calculated frequencies deviated less than 3% from the experimental frequencies for all of the functionals when the augmented correlation consistent basis sets were used. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011