Ab initio HF versus semi-empirical results of chemisorption calculations of hydrogen on graphite

The regular chemisorption of hydrogen on graphite in four different configurations has been studied with a Hartree-Fock ab initio technique. No stable phase was found; previous CNDO calculations indicated stable adsorption to occur in three cases out of four. However, the positions of relative minima and the corresponding electronic structure are reasonably described by the semi-empirical scheme.