Intermolecular potential surfaces from electron gas methods. I. Angle and distance dependence of the He–CO2 and Ar–CO2 interactions

Abstract

Angle dependent intermolecular potential energy surfaces suitable for use in studies of rotationally inelastic collisions of rigid linear CO2 with Ar and He are calculated using the electron gas model to obtain the short range interactions and joining them smoothly to the long range van der Waals tails of the preceding paper. Smooth analytic fits to the potentials, convenient for use in scattering calculations, are given. The surfaces are very strongly nonspherical. Virial coefficients calculated using the a priori He–CO2 potential are in excellent agreement with experiment, and a simple adjustment of the Ar–CO2 potential gives excellent agreement with both virial coefficients and a potential inferred from high energy scattering data.