I am interested in the theoretical study of optical anisotropy (birefringence, dichroism etc.) of different materials. I have seen DFT works studying optical anisotropy from the calculation of dielectric function (An example). However DFT is a ground-state theory and is not considered the best for optical studies. My question.
What are the different methods available for the study of optical anisotropy and how do they compare with DFT?