A comparison of electronic properties of various modifications of graphite

We have investigated various electronic band structures for different graphite modifications using the extended tight binding method. The specific crystal structures studied are the two naturally occurring graphite modifications (Bernal and rhombohedral), and a hypothetical configuration where the carbon atoms in consecutive layers are directly above each other. The latter structure has not been observed in pure graphite, but it is the backbone structure for different stages of intercalated graphite, e.g. Li-graphite compounds LiC_n. On comparing band structures for various graphite modifications we find important differences in the π-bands close to the Fermi energy, the region dominating transport and low energy excitation properties.