Theoretical studies of the potential energy surfaces and rotational spectra of Kr/Xe–CS2 complexes

Abstract

Theoretical studies of potential energy surfaces and bound states were performed for Kr/Xe–CS2 complexes. The two intermolecular potential energy surfaces (PESs) for the Kr/Xe–CS2 complexes were constructed from ab initio data points at the CCSD(T) level. The two PESs have similar features, characterized by a global T-shaped minimum and two equivalent local linear minima, along with the saddle points between them. Based on our ab initio PESs, bound state calculations were performed, and several intermolecular vibrational states were assigned unambiguously by analyzing the wavefunctions. The average structural parameters were determined, and the rotational frequencies for the transitions with J=0–5 were predicted. The rotational constants (A, B, and C) were determined by fitting the energy levels to the Hamiltonian of an asymmetric top and were found to be reliable. The band origin shifts for Kr/Xe–CS2 complexes were predicted based on the Buckingham potential. These calculated results could be useful in the experimental study of the microwave spectra of Kr/Xe–CS2 complexes.