Molecular collisions. XIX. The distorted wave approximation to atom-rigid symmetric top rotational excitation

In Paper XVII of this series an exact formalism describing nonreactive collisions of vibrating polyatomic molecules was developed. The present work specializes this formalism to the case of an atom-rigid symmetric top collision. A distorted wave approximation is developed which is appropriate for a symmetric top in which the moment of inertia about the symmetry axis is much smaller than that about the remaining principal axes. The solution obtained is then expressed in terms of the generalized phase shift formalism.