Exciton effects on the nonlinear optical properties of the endohedral La@C82complex

Using the Hartree-Fock single-excitation configuration interaction (CI) model, we calculated the second-order and third-order nonlinear polarizability of the La@C82 molecule. Obtained results indicate that the third-order nonlinear polarizability c is much larger than the second-order nonlinear polarizability b and linear polarizability. Also, our results show that the c value of the La@C82 molecule is much larger than those of the C60 and C70 molecules. The spectral shapes of the third-order nonlinear polarizability tensor, the second-order nonlinear polarizability tensor and linear polarizability of the C82 molecule turn out to be determined mainly by the geometrical distributions of the pentagons in the fullerene structures.