COHESIVE MECHANISM AND ENERGY-BANDS OF SOLID C60

We present microscopic total-energy calculations which provide a cohesive property and electronic structures of a new form of solid carbon, the face-centered-cubic C60 crystal (fcc C60). We find that C60 clusters are condensed by van der Waals force, and that the resulting fcc C60 is a novel semiconductor with direct energy gap of 1.5 eV at the Brillouin-zone boundary (X point). We also find that an "impurity" C60K cluster induces a shallow donor state in fcc C60.