  The majority of fulleride superconductors with unusually high
transition-temperature to kinetic-energy ratios have a face-centred-cubic (FCC)
structure. We demonstrate that, within extended Hubbard models with strong
Coulomb repulsion, paired fermions in FCC lattices have qualitatively different
properties than pairs in other three-dimensional cubic lattices. Our results
show that strongly bound, light, and small pairs can be generated in FCC
lattices across a wide range of the parameter space. We estimate that such
pairs can Bose condense at high temperatures even if the lattice constant is
large (as in the fullerides).
