HeHF scattering cross sections from an ab initio SAPT potential: confrontation with experiment

Differential and integral cross sections for elastic and rotationally inelastic HeHF scattering are obtained by means of converged close-coupling calculations from an ab initio potential computed by symmetry-adapted perturbation theory (SAPT). These results are compared with total differential cross sections from crossed-beam time-of-flight measurements and with state-to-state integral cross sections for the rotational excitation of HF by collisions with He. It is found that the SAPT potential, which was already shown to be accurate in a comparison with the high-resolution infrared spectrum, yields accurate scattering cross sections as well. A slight scaling in the anisotrophy of the potential, which gave better line widths in the spectrum for those levels that undergo rotational predissociation, gives a marginal improvement of the rotationally inelastic cross sections.