The enumeration of reaction pathways using Burnside's lemma

A simplified method for the calculation of molecular correlation energies, developed previously, is applied to the study of the potential energy hypersurface related to the reaction O₂+H→HO₂→OH+O. The main parameters that characterize the topology of the surface have been determined: the equilibrium geometries and vibrational frequencies of HO₂ and of its dissociation products, the dissociation energies, the energy gap between the dissociation limits, the geometry of an activated complex, and the corresponding potential barrier height. The particular importance of including the correlation energy is discussed for each of the calculated parameters. In spite of the minimal computational effort required, the results are in good agreement with the experimental data on the one hand, and with the results proceeding from elaborate variational calculations on the other hand. Moreover the controverted existence of a potential barrier (0.19 eV) along the O₂+H→ HO₂ recombination path is discussed.