NONBONDING ORBITALS IN GRAPHITE, CARBON TUBULES, TOROIDS AND FULLERENES

It is shown that the non-bonding orbitals of many graphite-derived car bon frameworks can be understood in terms of the four non-bonding orbi tals of the graphite sheet. Several infinite series of fullerenes with non-bonding orbitals are identified, and the frontier orbitals of ico sahedral fullerenes rationalised, by considering fullerenes as cut and folded graphite. The leapfrog construction, which produces only close d-shells when acting on fullerenes, is shown in contrast to produce ex actly the metallic tubules and the open-shell polyhex toroids when act ing within these families.