Nonadiabatic Calculation For The Reaction Of F(2～P) With H₂ And Its Isotopic Variants

As the paradigm for exothermic triatomic reactions, the reaction of F(2^P) withH₂ and its isotopic variants are important elementary reactions in gas phase reactiondynamics. The nonadiabatic time-dependent wave packet and RPD (reactant-productdecoupling) calculation including the electronic spin and orbit angular momenta ofthe F atom, which are extensions of the adiabatic work, are applied to study thereactions on the ASW(Alexander-Stark-Werner) potential energy surfaces.In the calculation for the nonadiabatic F(2^P_3/2, P_1/2) + H₂ reaction, it is foundthat Coriolis coupling and electronic coupling potential have a relatively minor effecton the reactivity from the ground state at lower translational energy, but a nonnegligible one at higher translational energy. The electronic coupling potential has anunambiguous effect on the reactivity of the excited spin-orbit state, while thecontribution of Coriolis coupling to the reactivity of the excited spin-orbit statewould be very little. For the F (2^P_3/2, 2^P_1/2) + HD reaction, the total integral crosssections of the spin-orbit ground and excited states for the two possible products arecalculated. The resonance peak in the present average cross section for the HF+Dproduct is slight larger than the experimental result, but much smaller than that of thesingle-state calculations on the SW potential energy surface. It seems that thespin-orbit coupling would play a relatively important role in this reaction. For thereaction of F (2^P_3/2, 2^P_1/2) with D₂ (v=j=0), the multi-states integral cross sections ofthe spin-orbit ground and excited state and the total average rate constant arecalculated. Because the contributions of the rate constant for the spin-orbit excitedstate to the total average rate constant are very small, the rate constant of thespin-orbit ground state is similar to the total average one. Further more, we carry outa nonadiabatic state-to-state RPD calculation to study the reaction of F (2P1/2) withH2 for the total angular momentum of J=0.5 including the electronic spin-orbitcoupling. In our calculation, the total state-to-state reaction probability, the reactionprobability of the vibrational state, the reaction probability of the rotational state andthe distribution of the rotational state for the v=2 and 3 at three different collisionenergies are presented.