Spin-orbit effect in the energy pooling reaction O2(a 1Δ)+O2(a 1Δ)→O2(b 1Σ)+O2(X 3Σ)

Five-dimensional nonadiabatic quantum dynamics studies have been carried out on two new potential energy surfaces of S-2((1)A') and T-7((3)A '') states for the title oxygen molecules collision with coplanar configurations, along with the spin-orbit coupling between them. The ab initio calculations are based on complete active state second-order perturbation theory with the 6-31+G(d) basis set. The calculated spin-orbit induced transition probability as a function of collision energy is found to be very small for this energy pooling reaction. The rate constant obtained from a uniform J-shifting approach is compared with the existing theoretical and experimental data, and the spin-orbit effect is also discussed in this electronic energy-transfer process. (c) 2007 American Institute of Physics.