A study of long-range anisotropic potentials for CsF, CsCl, and KCl interacting with the rare gases based on measured state-to-state rotationally inelastic cross sections. II. Comparison with calculations for model potentials

In a previous paper measurements of state-to-state rotational excitation cross sections for small angle scattering for the systems CsCl and KCl colliding with rare gases were reported. In the present paper the latest available theoretical models for calculating the long-range potentials are used in the framework of the Rittner model to obtain an accurate anisotropic potential including terms up to R−9 and anisotropies up to P5 (cos γ) (γ is the angle between the internuclear distance R and the bond axis) for CsF, CsCl, and KCl interacting with all the rare gases. With these potentials, inelastic cross sections are calculated in the IOS approximation and averaged over the apparatus geometry for direct comparison with the experiemntal data. The comparison shows good agreement within about 30% for CsF and CsCl, where classical induction terms dominate with significantly smaller theoretical cross sections for KCl. Since for KCl the anisotropic dispersion terms are expected to be dominant, the results suggest either that the small amount of covalent bonding has a severe effect on the potential or that the available theoretical methods do not describe the anisotropic long-range potential.