  In this paper we discuss more wide applicability of the Chandrasekhar model
of coupled oscillators in the optical rotatory dispersion of the crystals. We
solve the problem using the Chandrasekhar model of two coupled oscillators in
the case when we include all couplings between adjacent oscillators on the
helix that is given by the crystal structure. Further we discuss the results of
coupled oscillators models in the case of the including of the couplings
between even and odd oscillators on the helix. The optical rotatory dispersion
results obtained after the approximations of the oscillator strengths verify
that these couplings have the important influence on the crystal optical
rotatory dispersion.
