S(1D) + ortho-D2 Reaction Dynamics at Low Collision Energies: Complementary Crossed Molecular Beam Experiments and Theoretical Investigations

The excitation function of the S(1D) + D2 reaction was determined in a crossed molecular beam apparatus for collision energies ranging from 1817 to 47 J mol–1 in the near-cold regime. A very good overall agreement was found between experimental data and the theoretical results obtained using the ab initio potential energy surface built by Ho and coworkers and different methods: time-independent quantum dynamics (QM), semiclassical mean potential capture theory (sc-MPCT), and quasi-classical trajectories (QCT). The general trend of the experimental excitation function is well reproduced in most of the range by a simple capture calculation with an R–6 dispersion potential. The present results are discussed in the light of previous studies on the isotopic variants S(1D) + H2 and HD.