Quantum scattering calculations for the electronically nonadiabatic Br(2P1/2)+H2→HBr+H reaction

Abstract

Three-dimensional quantum scattering calculations have been carried out for the electronically nonadiabatic Br(2P1/2)+H2→HBr+H reaction. The calculations have been done using two methods: the time-independent hyperspherical close-coupling formalism for the total angular momentum quantum number J=0 and the generalized R-matrix propagation method with negative-imaginary potentials which absorb the reactive flux for J⩾0, but employing the coupled-states approximation for J>0. The (2×2) diabatic model, which was originally developed by Truhlar and co-workers, has been employed in the present calculations. The results calculated with the two methods agree very well with those obtained by Truhlar and co-workers, indicating that our results are numerically converged. Detailed analyses of the calculated probabilities show that the electronically nonadiabatic transitions from Br(2P1/2)+H2(ν) to Br(2P3/2)+H2(ν+1) effectively occur in the entrance region of the potential surface but that the contribution of the electronically nonadiabatic chemical reaction, Br(2P1/2)+H2(ν)→HBr+H, is small.