Ring polymer molecular dynamics of the C(1D)+H2 reaction on the most recent potential energy surfaces

Abstract

Ring polymer molecular dynamics (RPMD) calculations for the C(1D)+H2 reaction are performed on the Zhang-Ma-Bian ab initio potential energy surfaces (PESs) recently constructed by our group, which are unique in very good descriptions of the regions around conical intersections and of van der Waals (vdW) interactions. The calculated reaction thermal rate coefficients are in very good agreement with the latest experimental results. The rate coefficients obtained from the ground ã1A′ ZMB-a PES are much larger than those from the previous RKHS PES, which can be attributed to that the vdW saddles on our PESs have very different dynamical effects from the vdW wells on the previous PESs, indicating that the RPMD approach is able to include dynamical effects of the topological structures caused by vdW interactions. The importance of the excited b̃1A″ ZMB-b PES and quantum effects in the title reaction is also underscored.