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Coupled‐cluster study of the equilibrium geometry and harmonic vibrational frequencies of the methyl radical
Author(s) -
RobertoNeto Orlando,
Chakravorty Subhas,
Machado Francisco B.C.
Publication year - 2005
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.20534
Subject(s) - extrapolation , coupled cluster , chemistry , methyl radical , atomic physics , harmonic , valence (chemistry) , electron , valence electron , computational chemistry , physics , quantum mechanics , molecule , mathematics , mathematical analysis , radical , organic chemistry
Accurate equilibrium geometries, harmonic vibrational frequencies, and equilibrium rotational constants of the methyl radical were computed using coupled‐cluster theory in combination with the cc‐pV n Z and cc‐pCV n Z basis sets of Dunning. Valence and all electron calculations were carried out. Using all electron correlations and CBS extrapolation, the r e value is equal to 1.0758 Å, which is 0.0032 Å shorter than the experimental value of r 0 (1.079 Å). The harmonic (ω 1 , ω 2 , ω 3 , and ω 4 ) frequencies calculated using the CBS extrapolation differ from the experimental fundamental frequencies, respectively, by +142, +125, +21, and –82 cm −1 . © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005