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Density functional studies of AnF 6 (An=U, Np, and Pu) and UF 6− n Cl n ( n =1–6) using hybrid functionals: geometries and vibrational frequencies
Author(s) -
Han YoungKyu
Publication year - 2001
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.1149
Subject(s) - bond length , molecule , density functional theory , chemistry , molecular vibration , force constant , atomic physics , hybrid functional , computational chemistry , molecular physics , physics , organic chemistry
We have compared the performance of widely used hybrid functionals for calculating the bond lengths and harmonic vibrational frequencies of AnF 6 (An=U, Np, and Pu) and UF 6− n Cl n ( n =1–6) molecules using “small‐core” relativistic effective core potentials and extended basis sets. The calculated spectroscopic constants compare favorably with experimental data for the bond lengths (average error ≤ 0.01 Å) and vibrational frequencies (average error ≤ 7 cm −1 ) of the AnF 6 molecules. The experimental vibrational frequencies of the stretching modes were available for most of the UF 6− n Cl n ( n =1–6) molecules. The calculated vibrational frequencies are in good agreement with the experimental data to within 4.6 cm −1 and 7.6 cm −1 for selected Becke1 and Lee, Yang, Parr (B1LYP), and Becke3 and Perdew, Wang (B3PW91) functionals, respectively. We conclude that one can predict reliable geometries and vibrational frequencies for the unknown related systems using hybrid density functional calculations with the RECPs. The geometries and vibrational frequencies of the UF 6− n Cl n ( n =1–6) molecules that have not been determined experimentally are also presented and discussed. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 2010–2017, 2001