Calculations of two-photon absorption cross-sections of stibene and bis (styryl) benzene derivatives by means of TDDFT-SOS method

In this benchmark study, we employ time-dependent density-functional theory (TDDFT) combined with sum-over-states (SOS) method to calculate the two-photon absorption cross-sections in a series of stibene and bis (styryl) benzene derivatives. Calculated excitation energies corresponding to one-photon absorption maxima are found to be in good agreement with experiment. The evaluated two-photon absorption cross-sections also agree with experimental data. We concluded that the TDDFT-SOS method is a numerically efficient quantitative calculation method for nonlinear polarizabilities of stibene and bis (styryl) benzene derivatives.