A tight-binding description of the hopping integrals between the C60 molecules has been developed (Phys. Rev. Lett. 67 , 3002 (1991)) and used to obtain a description of the t1u band in terms of hopping integrals between t1u orbitals on neighboring molecules ( Phys. Rev. B 46 , 1773 (1992)). This description has also been extended to the t1g and hu bands ( Phys. Rev. B 51 , 17446 (1995) ). The overall hopping strength is fitted to LMTO band structure calculations to reproduce the band widths. The accuracy of these models is illustrated by a comparison with a full band structure calculation for a C60 solid.

The C60 molecules in A3C60 can take two different orientations. An Ising model was developed to describe the energetics of the corresponding orientational disorder.

The hopping integrals to the alkali atoms in AnC60 have been parameterized and the effects on the t1u band has been studied Phys. Rev. B 57, 2159 (1998). A tight-binding model for studying the deviations from stoichiometry in A3-xC60 was developed .