THEORETICAL STUDY OF NON-REACTIVE $Li + H^{2}$ COLLISION DYNAMICS

Abstract

Four types of ab initio calculations were used to determine four sets of potential energies of a common set of geometries for the Li + $H_{2}$ collision system. The four calculations involved choices between a moderate and a large basis set and between the Hartree-Fock (HF) and the multi-configuration-self-consistent field (MCSCF) methods. An analytic functional form was separately least squares fit to each set of potential energies to produce four analytic potential energy surfaces. Classical trajectories at energies below the reaction threshold were run on each surface The trajectories were analyzed for inelastic cross sections, differential cross sections, and energy loss as a function of angle. The results were used to evaluate both the dynamics and the accuracy and usefulness of each type of surface calculation.