Nature of second-order nonlinear optical response in phthalocyanine derivatives: a density functional theory study

Density functional theory was employed to investigate a series of phthalocyanine derivatives, discovering the limitation when the expansion of the conjugated system was employed to improve the hyper-Rayleigh scattering response coefficient. Furthermore, an unusually C-infinity upsilon-type octupolar population was found by electrostatic potential analysis. In addition, the dynamic and static hyper-Rayleigh scattering responses (beta(H RS)) were simulated using the coupled perturbed density functional theory, showing an increasing dynamic beta(H RS) value along with an increase in incident light energy.