A quasiclassical trajectory and quantum mechanical study of the O(1D) + D2 reaction dynamics. Comparison with high resolution molecular beam experiments

Abstract

A theoretical study of the dynamics of the O(¹D) + D₂ 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 1¹A′, 1¹A″ and 2¹A′ potential energy surfaces (PES) by Dobbyn and Knowles. The quasiclassical trajectory (QCT) method was used for the investigation on the ground electronic PES (1¹A′). Non-adiabatic transitions between this PES and the excited 2¹A′ were considered by using a trajectory surface hopping methodology. An accurate quantum mechanical (QM) approach was used for the reaction on the excited 1¹A′ PES. The theoretical results are globally in good agreement with the measurements and indicate that, although the excited 1¹A″ 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 1¹A′ PES.