Crystal optics and raman intensities

The theory of Raman scattering intensities is modified to take account of crystal optics. The radiation at a long distance from an oscillating electric dipole in a dielectric continuum is calculated for propagation along or perpendicular to a principal dielectric axis. The results are combined with results on the effect of transmission through the crystal surface to give an expression for the polarized Raman intensity in an orthogonal axis system with only one axis a principal dielectric axis. For 90° scattering in monoclinic crystals in the abc′ axis system, there may be up to three different intensity patterns for a given polarization, yielding ten distinct crystal settings. Sample calculations for naphthalene show that the intensity patterns for the same polarizations in distinct settings differ only slightly, and this will normally be the case.