Charge transfer, polarizability and stability of Li-C60 complexes

Ab initio Hartree-Fock calculations, using the 6-31G basis set, have been performed for the Li-C-60 endohedral and exohedral complexes. Atomic coordinates are generated by positioning the lithium atom along four trajectories perpendicular to the surface of the cage, leading to a total of 60 endohedral and 80 exohedral configurations. It was found that the Li atom is fully or partially ionized in the C-60 cavity depending on the position. Distribution of the donated electron from the metal on the surface of C-60 was computed to determine charge transfer and polarization of C-60 upon metal doping. The off-center stabilized Li@C-60 configuration found in this work is in agreement with previous investigations. (C) 1998 Elsevier Science B.V.