Dependence of Polarizability and Diamagnetic Susceptibility on the Order Parameter D

In nematic liquid crystals consisting of molecules which deviate from cylindrical symmetry the molecular order cannot be completely characterized by the order parameter s alone, but the order parameter D is required additionally. It is shwon here, that the diamagnetic susceptibility, the polarizability, and hence the refractive index depend on S as well as on D, and that the usually applied evaluation gives a combination of these.