Depolarization ratio of Rayleigh scattered radiation by molecules.

The depolarization ratios of Rayleigh scattered radiation by molecules has been used to measure the ratio of anisotropic polarizability to isotropic (average) polarizability in the laboratory. The authors have calculated the depolarization ratio for N2, CH3Cl, and H2O from the first principles. It is shown that the depolarization ratio derived from input polarizabilities differs by a factor of about 4 for 1Sigma diatom N2, by a factor of about 2.9 for symmetric top CH3Cl, and by a factor of about 5 for asymmetric top H2O. These large discrepancies arise because in deriving the ratio of anisotropic polarizability to isotropic (average) polarizability from the measured depolarization ratio, the constraints imposed by the conservation of angular momentum have been completely ignored.