ELECTRONIC-STRUCTURE OF HF-AT-C-28 AND ITS IONS .1. SCF CALCULATIONS

Ab initio restricted Hartree-Fock calculations were performed on the g round and excited states of Hf@C-28 and its positive and negative ions . Relativistic core potentials and symmetry-adapted functions were inc luded in the calculations to take into account the relativistic effect s of the heavy atom and to reduce the time and effort of the computati on. Ionization potentials, electron affinities, and excitation energie s of the systems were obtained and compared with experimental data or other theoretical values where available. The binding of Hf of C-28 is discussed in terms of the MO interaction diagram, population analysis , flow of electrons between Hf and C-28, and redistribution of electro ns within C-28. These factors that affect the bonding between Hf and C -28 can also shed light on the characteristics of the bonding of endoh edral complexes of fullerenes in general.