Electronic structure and properties of light atoms intercalated in graphite

Abstract

Using the extra-orbital model, the authors calculate the electronic structure of one or two atoms of Li, Be, B, C or N, represented by 2s-2p orbitals, intercalated between graphite layers. To do so, (i) they have regenerated the pi -band structure of 2pz states in pure graphite within a Slater-Koster scheme; (ii) they have calculated the corresponding intersite Green functions within the corresponding D3h symmetry point group; and (iii) they have computed the transfer integrals between the intercalated atom and a neighbouring carbon atom by using the basic two-centre atomic integrals. Within the authors' simple model they discuss the natures of the various electronic situations in terms of the various types of impurities considered. Finally they calculate the electronic binding energies of the corresponding diatomic intercalated molecules (Li2, Be2, C2, N2) with respect to the differing geometrical configurations.