Fullerene structures with symmetrically arranged pairs of pentagonal–heptagonal defects had been proposed in order to explain the round form of giant multilayer fullerene cages. Although the proposed cages were defective, they belonged to the icosahedral point group. By using the Tersoff–Brenner potential, calculations were made of the shape of defective fullerenes. It was found that these fullerenes had a rounder shape than did structures without defects. The electronic structure of the fullerenes with defects was also calculated within the Hückel approach. The electronic structures were closed and the energy gaps between bonding and antibonding orbitals were higher, than those for fullerenes with no defects, in almost every case considered.

Fullerenes with Symmetrically Arranged Defects - Geometry and Electronic Structure. A.Pérez-Garrido, J.D.Catalá, F.Alhama: Physics of the Solid State, 2002, 44[3], 598-9