Regular chemisorption of hydrogen on graphite in the crystalline orbital NDO approximation

Abstract
A Hartree–Fock treatment of the regular chemisorption of hydrogen on a graphite monolayer in a crystalline orbital NOO approximation is presented. The computational problems concerning the full exploitation of the point symmetry of the lattice, as well as the integration procedures are the same as encountered in a corresponding ab initio treatment. Three different cases have been considered, corresponding to the chemisorption of one hydrogen atom per unit cell: (A) above alternate carbon atoms; (B) above the center of a C–C bond; (C) at the center of a carbon ring. Bound states are found to occur only for cases A and B. The electronic features of the adsorbent–adsorbate system are appreciably differentiated. Such differences are discussed by using energy band structures and total and partial density of states spectra.