Electronic structure of superconductingBa6C60

We report the results of first-principles electronic-structure calculations for superconducting ${\mathrm{Ba}}_6$ ${\mathrm{C}}_{60}$. Unlike the ${\mathit{A}}_3$ ${\mathrm{C}}_{60}$ 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.