Chain-orientation dependence of electronic structure of RbC60 crystal

The electronic structure of RbC60 polymeric phase crystal of the space group of I2/m has been studied based on the tight-binding crystal orbital (CO) calculation including both σ and π electrons. It has been found that the change in the chain orientation drastically varies the electronic structure of the RbC60 crystal. In particular, for a certain range of chain orientation angle (θ=85–90°), it has become clear that the electronic structure is of quasi-one-dimensional (1D) and is developed in the direction perpendicular to the polymer axis. For θ=90°, e.g., there appears sufficient nesting property of the Fermi surface. This situation could explain the quasi-1D characteristics experimentally found for various electronic phases.