Semiclassical treatment of electronic transitions in molecular collisions: Three-dimensional H + + D 2 → HD + + D

Abstract

A semiclassical study is carried out for the three-dimensional reaction H + + D 2 → HD + + D, which involves an electronic transition from the ground to the first excited singlet state of the H 3 + system. The potential energy surfaces corresponding to the two singlet states exhibit an avoided intersection, and they are analytically continued into the complex nuclear coordinate plane. S-matrix elements in the classical limit are computed from complex-valued classical trajectories which propagate on the analytically continued surfaces and switch surfaces continuously at the complex intersection. These elements are computed for the transition from the ground rotational and vibrational states of D 2 to the ground rotational and first excited vibrational states of HD + for zero total angular momentum and for energies in the range from 4.0 eV to 5.0 eV relative to the bottom of the D 2 well on the lower surface.