Rate Constants of the H + HCF3 → H2 + CF3 Reaction from Ring Polymer Molecular Dynamics on a Highly Accurate Potential Energy Surface.

Abstract

The reaction between H and HCF3 is the primary consumption pathway of HCF3 in the atmosphere and combustion. In this work, ring polymer molecular dynamics (RPMD) calculations are performed to calculate the rate constants of the reaction on a recently developed accurate potential energy surface. 36, 20, and 8 beads are used to compute the rate constants at 350 K ≤ T < 800 K, 800 K ≤ T ≤ 1000 K, and T > 1000 K, respectively. The obtained RPMD rate constants agree well with the experimental measurements. In addition, a detailed analysis of the free-energy curves and transmission coefficients reveals that the quantum tunneling significantly affects the reaction dynamics, even at high temperatures.