HCl rotational excitation by Ar impact: Quasiclassical close coupling approximation for atom–diatomic molecule scattering

Abstract

We apply quasiclassical approximations for the relation motion degree of freedom to full quantum mechanical space fixed close coupling equations. This approximation is carried through in the context of atom–diatomic molecule rotational excitation collisions. Criteria for the validity of these approximations are described. We apply the method to treat Ar HCl collisions using previously suggested potential energy surfaces. The importance of diffraction, rotational inelasticity, and various features of the potential energy surface for state to state differential and integral cross sections are discussed.