Ab initio theoretical studies of the CH2 + H .dblharw. CH3* .dblharw. CH + H2 reactions

Abstract

Ab initio electronic structure characterizations of the reactants and parts of the addition reaction path for the title reaction are described. The wave function allows extensive correlation of all seven of the valence electrons via a CASSCF plus single- and double-excitation configuration interaction expansion. A large correlation-consistent basis set (triple valence plus polarization) is used. The calculated properties of the reactants and of CH{sub 3} compare favorably to experiment. Variational transition state theory calculations suggest little temperature dependence to the high-pressure limiting rate constant for CH{sub 2} + H addition.