Hyper-Rayleigh scattering from correlated molecules.

The polarization dependence of hyper-Rayleigh scattering has been calculated for spherical domains of orientation correlated molecules. Distributions with radial or azimuthal mean polar orientation of the molecules are found that give results consistent with experimental observations, and expressions for the polarization ratios in terms of the product of correlation strength and correlated domain size are derived for these distributions. Assuming a plausible correlation strength, it is estimated that the correlated domain size in typical polar liquids is of order 100 molecular diameters.