Theory and computation of optical rotatory power in inorganic crystals

The classical polarizability theory of optical activity in crystals is elaborated and a method of calculating rotatory power from crystal structure data is described. By varying the polarizabilities of the atoms within reasonable limits, optical rotatory powers are computed for crystals of α-quartz, AlPO₄, cinnabar, Bi₁₂SiO₂₀, Bi₁₂GeO₂₀, α-LiIO₃, NaClO₃ and NaBrO₃. In general, the agreement between theory and experiment is excellent. As expected, considerable variability in polarizabilities is required in different structures in order to obtain satisfactory fits to the observed refractive indices and rotatory powers. The orientations of anisotropic polarizability ellipsoids derived in the course of the calculation are compared with those suggested earlier by Glazer & Stadnicka [J. Appl. Cryst. (1986), 19, 108-122].