Introduction

The fullerite allotrope of carbon, C60, has been of considerable interest because of possible chemical and biological applications and because of the superconductivity at 33K in its alkali-doped compounds. The use of Gaussian basis set in GDS/DFT has the advantage since all electronic properties are directly expressed in terms of local orbitals. This facilitates a tight-binding interpretation and is useful for extracting parameters for model studies of superconducting mechanism. The structure of Ih C60 can be described by two parameters, the short carbon-carbon bond distance R1 and the longer bond R2. Electronic structural properties of C60 has been studied by several authors (e.g., Shirley and Louie, 1992) using plane-waves with pseudo potential approximation, and more recently by ourselves using GDS/DFT including all electrons (PRB, Vol. 52, 2348 (1995)).