Interaction Potential between Li+ and HD: Region for Rotational Excitation Cross Sections

The interaction potential between Li
⁺
and HD (with internuclear separation fixed at 1.4 a.u.) was determined by two different methods using the results of a recent self-consistent-field calculation of the potential energy surface for Li
⁺
-H
2
. In one method, Li
⁺
-HD interaction energies were obtained utilizing an analytical representation of the Li
⁺
-H
2
surface. The second method used ab initio Li
⁺
-H
2
interaction energies directly to yield the Li
⁺
-HD potential surface by means of interpolation procedures. The interaction potentials determined by the two methods are essentially identical and have been fit to an analytical form, V(r,θ) = ∑
l
v
l
(r)P
l
(cos θ), to facilitate scattering studies. For large center of mass distances, perturbation theory is in good accord with the potentials constructed by the two procedures.