ELECTRONIC AND GEOMETRIC STRUCTURES OF C70

We have calculated the electronic structure of the C70 cluster of the D5h geometry by the local-density approximation. The electronic levels obtained show excellent agreement with photoemission experiments, which provides a further strong support for this geometry. The bunching of levels is observed at several energies, including the regions around the highest-occupied state and the lowest-unoccupied state, showing the possibility of superconductivity in doped solid C70. The total-energy calculation suggests that the bond-length alternation found in C60 is also present in C70. The calculated binding energy per atom of the C70 cluster is found to be slightly larger than that of the C60 cluster. This implies the importance of dynamical effects on the relative abundance of fullerenes.