The Revised Quantum Mechanical Theory of the Optical Activity of   Crystals
  In this paper we present the revised view on the optical activity of crystals based on the model of two dumped coupled oscillators. The results are compared with the results of the same problem solved before and it is presented that the results of the quantum mechanical model are the generalization of the classical model only and they do not introduce the new terms of quantum mechanical nature. The results are discussed with regard to the rotational strengths of normal modes of vibrations and the formula for the complex rotatory power containing the rotational strengths is presented. 
I. Vysin, J. Riha