Time-dependent Hartree-Fock calculations of the quadratic polarizability dispersion for molecules with pronounced nonlinear optical properties

The quadratic huperpolarizability for the second harmonic generation is calculated at the fundamental frequencies 0, 0.656, 0.941, and 1.165 eV for three classes of organic molecules in the framework of the time-dependent Hartree-Fock perturbation theory. The π-electron approximation used reproduces available experimental data quite satisfactory. It is shown that the computation scheme earlier proposed is readily applicable to molecules of real physical interest.