Polarizability of phthalocyanine based molecular systems: A first-principles electronic structure study

A first-principles electronic structure study is performed to determine the optical and static polarizability tensors of various phthalocyanine (Pc) derived molecules, including $H2Pc$⁠, CuPc, and MgPc. It is found that the dominant contribution to the polarizability is electronic in origin, and that the metal atoms only marginally enhance the polarizability. An analytical electrostatic model that relates the polarizability of an ellipsoid to its permittivity is then used to estimate the permittivity tensor of these molecular systems.