Electronic Structure of Electron-Doped Fullerenes

Theoretical investigation of the electronic structure of C₆₀ fullerene complexes with two lithium atoms and of nitrogen-doped fullerenes was performed, with the purpose of their subsequent comparison and study of an isomeric effect for the compounds in question. Both types of compounds have a donor level within the band gap, arising from the extra electron pair present in molecules. However, lithium-containing complexes possess another distinction, namely, a significant splitting of the energy levels caused by positively charged lithium atoms. The band-gap width and the average bond energy for the complex of the fullerene with lithium depend on both the nature of the polygon that coordinates the lithium atoms and the distance between the intercalated atoms. The same dependence is observed for the nitrogen-doped compounds, although it is of irregular character.