Ab initio calculations of endo-and exohedral C60 fullerene complexes with Li+ ion and the endohedral C60 fullerene complex with Li2 dimer

The results of ab initio Hartree-Fock calculations of endo-and exohedral C 60 fullerene complexes with the Li + ion and Li 2 dimer are presented. The coordination of the Li + ion and the Li 2 dimer in the endohedral complexes and the coordination of Li + ion in the exohedral complex of C 60 fullerene are determined by the geometry optimization using the 3–21G basis set. In the endohedral Li + C 60 complex, the Li + ion is displaced from the center of the C 60 cage to the centers of carbon hexa-and pentagons by 0.12 nm. In the Li 2 dimer encapsulated inside the C 60 cage, the distance between the lithium atoms is 0.02 nm longer than that in the free molecule. The calculated total and partial one-electron densities of states of C 60 fullerene are in good agreement with the experimental photoelectron and X-ray emission spectra. Analysis of one-electron density of states of the endohedral Li + @C 60 complex indicates an ionic bonding between the Li atoms and the C 60 fullerene. In the Li + C 60 and Li + @C 60 complexes, there is a strong electrostatic interaction between the Li + ion and the fullerene.