TOPOLOGICALLY DETERMINED MIDGAP STATES IN AMORPHOUS-CARBON - 5-FOLD AND 7-FOLD RINGS

Using ab initio quantum chemical calculations, it was shown that the t opologically determined energy levels decrease the energy gap at E(F). It was demonstrated in examples that the presence or lack of five- an d sevenfold rings are not sufficient for the existence or non-existenc e of electronic states at the Fermi level within tight binding approxi mation.