A theoretical study on the lonic states and the photoelectron spectra of dichlorodifluoromethane (CF 2Cl 2)

Abstract

Ab initio calculations are performed to study the molecular equilibrium structure and the harmonic vibrational frequency of the low-lying four ionic states 2 B 2, 2 A 2, 2 B 1, and 2 A 1 of dichlorodifluoromethane (CF 2Cl 2). The theoretical intensity curve obtained from the Franck-Condon factors is in good agreement with the photoelectron, (PE) spectrum. The results show that the four maxima of the PE spectrum from the lower energy side correspond to the 2 B 2, 2 A 2, 2 B 1, and 2 A 1 states. Three vibrational progressions are found in the theoretical intensity curve of 2 B 2. Higher vibrational excitations to the ν 4 (ClCCl bending) mode contribute to all progressions and vibrational excitations of the ν 1 and ν 3 modes also contribute to intensity.