A generalized model for the ν-dependence of the anisotropic long-range attractive interaction of alkali dimer-atom systems

Abstract

State-selective measurements of anisotropic integral cross sections for the scattering of highly vibrationally excited alkali molecules (Li 2, Na 2) with various atoms (He, Ne, Ar, Kr, Na) are used to model simple three-dimensional potential hypersurfaces for these systems by comparison with quantum mechanical IOS scattering calculations. The two necessary fitting parameters in the attractive and repulsive part of the potentials are remarkably similar for all investigated systems and give new insight into the variation of potential energy with vibrational excitation. On the basis of this manifold of improved hypersurfaces, it is possible to account for the net increase in total cross section, anisotropy, and rotational inelasticity for vibrationally hot molecules by a single, generalized expression with a scaling parameter that includes collision energy and vibrational ground state potential well depth.