We report the results of first-principles electronic-structure calcula
tions for superconducting Ba6C60. Unlike the A3C60 superconductors, th
is new compound shows strong Ba-C hybridization in the valence and con
duction regions, mixed covalent-ionic bonding character, partial charg
e transfer, and insulating band structure, with a very small or zero g
ap within the local-density approximation.