Theoretical study of H chemisorption on NiO. Perfect surfaces and cation vacancies

Self-consistent Hartree-Fock and generalized-valence-bond calculations have been performed using a cluster model for H chemisorption on a NiO (001) surface. The binding energy of the H to Ni or O sites on the surface is found to be less than 0.75 eV while the binding energy to a cation vacancy on the (001) surface and on a crystallite corner is found to be 5.3-7.7 eV. These strongly bonded structures are found to be surface OH^- radicals.