Exploring the stereodynamics and microscopic mechanism of the O(3P) + CH4, CD4 → OH + CH3, OD + CD3 combustion reactions

The dynamics of the O(P-3) + CH4(X(1)A(1)) -> OH(X-2 Pi) + CH3(X(2)A(2)) reaction and its isotopic variant with CD4 was studied at several collision energies (E-col) of experimental interest, using the quasiclassical trajectory (QCT) method on the ground potential energy surface (GHMS PES). This ab initio analytical PES, previously developed using the O-X-(CX3) pseudo-triatomic approximation, allowed us to perform an exhaustive dynamics study of these low reactive systems. Around 300 million of trajectories were calculated to simulate the conditions of the low and intermediate E-col experiments. The results describe in detail scalar and vector properties and the reactive microscopic mechanism, obtaining a generally good agreement with the experiments. (C) 2015 Elsevier B.V. All rights reserved.