Article ID Journal Published Year Pages File Type
5415427 Journal of Molecular Spectroscopy 2009 8 Pages PDF
Abstract
We derived a general formula of Franck-Condon integral for two-dimensional harmonic oscillators (〈v1v2|v1′v2′〉) taking into account the Duschinsky effect and applied it to study the photoelectron spectroscopy of SO2 and SO2-. The equilibrium geometries and harmonic vibrational frequencies of SO2+, SO2 and SO2- were calculated by using the density functional theory (B3LYP functional) and the coupled cluster singles and doubles with perturbative triples [CCSD(T)] methods with various basis sets up to 6-311+G(3df) and aug-cc-pVTZ. The adiabatic ionization energy and electron affinity were computed by using the CCSD(T) method extrapolated to the complete basis set limit with aug-cc-pVXZ (X = D, T, Q, 5). The simulated photoelectron spectra of both SO2 and SO2- are in accord with the experiment. While the Duschinsky effect plays a role for some weak transitions of SO2, it can be neglected for SO2-. A splitting observed in the experimental photoelectron spectrum of SO2 is interpreted as contributing from hot bands and combination bands of ν1 and ν2, rather than arising from perturbation of a potential barrier as previous researchers proposed. The calculated adiabatic ionization energy and electron affinity are in agreement with the experiment within 0.027 and 0.040 eV, respectively.
Related Topics
Physical Sciences and Engineering Chemistry Physical and Theoretical Chemistry
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