Ring Polymer Molecular Dynamics Calculations of Thermal Rate Constants for the O([superscript 3]P) + CH[subscript 4] → OH + CH[subscript 3] Reaction: Contributions of Quantum Effects

Abstract

The thermal rate constant of the O([superscript 3]P) + CH[subscript 4] → OH + CH[subscript 3] reaction is investigated with ring polymer molecular dynamics on a full-dimensional potential energy surface. Good agreement with experimental and full-dimensional quantum multiconfiguration time-dependent Hartree results between 300 and 1500 K was obtained. It is shown that quantum effects, for example, tunneling and zero-point energy, can be effectively and efficiently included in this path-integral based approach implemented with classical trajectories. Convergence with respect to the number of beads is rapid, suggesting wide applicability for other reactions involving polyatomic molecules.