Theoretical Investigation of the Magnetic Dipole and Electric Quadrupole Contributions to the Second-Harmonic Generation in C60 and C70

Abstract

Abstract We develop the Valence Effective Hamiltonian method to calculate the magnetic dipole (MD) and electric quadrupole (EQ) contributions to the hyperpolarizability β of molecular systems. For both the C60 and C70 molecules, we find that the MD contribution leads to a β value which is several times larger than that of the EQ contribution. Taking into account the local field correction factor for C60 in solid state, we calculate x (2) susceptibility values that are in excellent agreement with recent experimental data.