Accurate Calculation of Rate Constant and Isotope Effect for the F + H 2 Reaction by the Coupled 3D Time-Dependent Wave Packet Method on the Newly Constructed Ab Initio Ground Potential Energy Surface.

We employ coupled three-dimensional (3D) time dependent wave packet formalism in hyperspherical coordinates for reactive scattering problem on the newly constructed ab initio calculated ground adiabatic potential energy surface for the F + H 2 /D 2 reaction. The convergence profiles for various reactive channels are depicted at low collision energy regimes with respect to the total angular momentum ( J ) quantum numbers. For two different reactant diatomic molecules (H 2 and D 2 ) initially at their respective ground roto-vibrational state ( v = 0, j = 0), calculated state-to-state as well as total integral cross sections as a function of collision energy, temperature dependent rate constants, and the kinetic isotope effect for various reactivity profiles of F + H 2 and F + D 2 reactions are presented along with previous theoretical and experimental results.