Roaming dynamics in the MgH + H→Mg + H2 reaction: Quantum dynamics calculations

Reaction mechanisms of the MgH + H→Mg + H2 reaction have been investigated using quantum reactive scattering methods on a global ab initio potential energy surface. There exist two microscopic mechanisms in the dynamics of this reaction. One is a direct hydrogen abstraction reaction and the other proceeds via initial formation of a HMgH complex in the deep potential well. The result of the present quantum dynamics calculations suggests that the HMgH complex formed in the reaction mainly decays into the Mg + H2 channel via a ‘roaming mechanism’ without going through the saddle point region.