Host-guest interaction in endohedral fullerenes

Ab initio calculations at the Hartree-Fock and second order Møller-Plesset Perturbation level using the 6-31G basis set show significant interaction between the C60 fullerene and species like H+ and H−, but much less interaction with Li+, He and H2. The influence of the guest species on the HOMO-LUMO energy gap and the electrostatic potential of the host cage is also discussed.