Electronic structure of superconducting Ba6C60

We report the results of first-principles electronic-structure calculations for superconducting Ba₆C₆₀. Unlike the A₃C₆₀ superconductors, this new compound shows strong Ba-C hybridization in the valence and conduction regions, mixed covalent-ionic bonding character, partial charge transfer, and insulating band structure, with a very small or zero gap within the local-density approximation.