Fermi Surfaces of Alkali-Metal-Doped C60 Solid

We present the first-principles electronic-structure calculation which provides outstanding features in the Fermi surface of K x C60. We have found that there exist two main Fermi surfaces: One is a hole pocket around the center of the Brillouin zone, and the other a large hole surface extending to the zone boundary. We have also found Fermi-surface nesting resulting in a peak at q=(1, 0, 0)2π/a in the susceptibility χ(q), which may induce an instability in this exotic material.