A quasiclassical trajectory and quantum mechanical study of the O(D-1)+D-2 reaction dynamics. Comparison with high resolution molecular beam experiments

A theoretical study of the dynamics of the O(D-1) + D-2 reaction has been performed at the collision energies (E-c = 86.7 meV and 138.8 meV) of a recent high resolution molecular beam experiment using the D-atom Rydberg tagging technique (X. Liu et al., Phys. Rev. Lett., 2001, 86, 408). The theoretical calculations have been carried out on the ab initio 1(1)A', 1(1)A and 2(1)A' potential energy surfaces (PES) by Dobbyn and Knowles. The quasiclassical trajectory (QCT) method was used for the investigation on the ground electronic PES (1(1)A'). Non-adiabatic transitions between this PES and the excited 2(1)A' were considered by using a trajectory surface hopping methodology. An accurate quantum mechanical (QM) approach was used for the reaction on the excited 1(1)A' PES. The theoretical results are globally in good agreement with the measurements and indicate that, although the excited 1(1)A surface does contribute to the reaction at the higher collision energy, a large part of the observed increase in backward reactive scattering is due to the reaction over the ground state 1(1)A' PES.