Cluster model study of the chemisorption of atomic hydrogen on the basal plane of graphite

The chemisorption of at. H on the basal plane of graphite was studied by both semiempirical and nonempirical Hartree-Fock methods employing finite cluster models. Geometric and energetic parameters obtained by these methods are generally in good agreement. Of various chemisorption sites, H atoms prefer the 1-fold coordination site which is the only site for which evidence was found for an exothermic process. Two-fold coordination corresponds to a saddle point when a 2nd layer is also considered in the graphite model.