An alternative method of dispersion relations derivation in the crystalline optical activity

An alternative method of the dispersion relations derivation in the crystalline optical activity, the theory of which is based on the models of coupled oscillators, is presented. The modified Rosenfeld relation for the complex rotatory power is used to avoid tedious calculations in other solution methods of this problem and therefore to make possible the solution of more complicated coupled oscillators models. In this relation, besides the summation over all optically active transitions also the summation over normal modes of vibrations of the coupled oscillators system has to be included. The rotational strengths of normal modes of vibrations are calculated by a relatively easy way. As an example of the applicability of this method the solution of the specific three coupled oscillators model, which is convenient for the description of the optical activity of crystals with space groups of symmetry D34 or D36, is presented. This used method is supposed to simplify the optical activity solution of crystals with arbitrary group of symmetry and also in the direction perpendicular to the optic axis.