ELECTRONIC-STRUCTURE OF C60 WITHIN THE TIGHT-BINDING APPROXIMATION

We study the electronic states of the molecule C60, with truncated icosahedral structure, using a simple tight-binding approximation. We compare our results for the energy levels with those obtained from a band-structure calculation within the local-density approximation (LDA). We find that using a value for the carbon-to-carbon electron-hopping matrix element t-pi = 2.50 eV, many of the features of the LDA calculation of the pi-electrons can be reproduced. We also study the effects of bond dimerization on the molecule's electronic spectrum and on the degeneracy of states near the molecular Fermi level.