VIBRATIONALLY AVERAGED POTENTIAL ENERGY SURFACES AND PREDICTED INFRARED SPECTRA OF THE He–18O13C18O AND He–16O13C16O COMPLEXES

摘要

Vibrationally averaged potential energy surfaces for isotopic He–CO2 complexes (He–18O13C18O and He–16O13C16O) are presented. Based on the latest ab initio potential of He–16O12C16O (Ran H, Xie D, J Chem Phys128:124323, 2008.) including the Q3 normal mode for the v3 antisymmetric stretching vibration of the CO2 molecule, the averaged potentials for both He–18O13C18O and He–16O13C16O are obtained by integrating the potential energy surfaces over the Q3 normal mode. The averaged potentials have T-shaped global minima and two equivalent linear local minima. The radial discrete variable representation/angular finitebasis representation method and Lanczos algorithm are employed to calculate the related rovibrational energy levels. The calculated band origin shifts of He–18O13C18O and He–16O13C16O are 0.1066 and 0.0914 cm-1, respectively, which agree very well with the observed values of 0.1123 and 0.0929 cm-1. The calculated rovibrational transitions of He–18O13C18O and He–16O13C16O are also in very good agreement with the available experimental spectra.