ELECTRONIC AND GEOMETRIC STRUCTURE OF C-72

Semi-empirical (MNDO) and ab-initio Hartree-Fock (3-21G) calculations on the structure and stability Of C72 are reported. Though never isola ted experimentally, C72 has been previously suggested to be a particul arly stable fullerene based on simple Huckel molecular orbital ideas. However, our calculations which include complete geometry optimization definitively show that it is significantly less stable than C70. The structural and electronic factors which are responsible for its instab ility are discussed.