THEORETICAL TREATMENT OF INTERNAL DYNAMICS IN VAN DER WAALS' MOLECULES

Abstract

An efficient method has boon developed for calculating ground state properties of atom-diatomic van der Waals’ complexes. The theory involves a decoupling of radial and angular motion analogous to the separation of electronic and nuclear motion in the Born-Oppenheimer approximation. This treatment furnishes rigorous upper and lower bounds to the ground eigenstate for a given potential surface. Good agreement was obtained with Dunker and $Gordon’s^{1}$ close-coupled calculations on the ArHCl complex. The efficiency of the method permits a hundred surfaces to be analyzed for their agreement with experiment in a matter of minutes on an IBM 360/91 computer. Using this procedure, a new ArHC1 surface was deter mined which fits the experimental data from molecular beam studies.