Kerr virial coefficients

T. K. Bose. A Comparative Study of the Dielectric, Refractive and Kerr Virial Coefficients. In G. Birnbaum (ed.). Phenomena Induced by Intermolec. Interactions, Plenum Press, New York, 1985, pp. 49-66. 

Refractive (Kerr) Second Virial Coefficients of Atomic Gases... 

Koch H, Hattig C, Larsen H, Olsen J, Jorgensen P, Fernandez B, Rizzo A (1999) The effect of intermolecular interactions on the electric properties of helium and argon. II. The dielectric, refrac-tivity, Kerr, and hyperpolarizability second virial coefficients. J Chem Phys 111 10108-10118... 

In the expressions (184) and (184b) the second, temperature-dependent term defines the Born effect due to superposition of the two non-linear processes of second-order distortion and reorientation of permanent dipole moments in the electric field. Buckingham et al. determined nonlinear polarizabflities If and c for numerous molecules by Kerr effect measurements in gases as a function of temperature and pressure. It is here convenient to use the virial expansion of the molar Kerr constant, when the first and second virial coefficients Ak and Bk result immediately from equations (177), (178), and (184). Meeten et al. determined nonlinear molecular polarizabilities by measuring K in liquids as a function of temperature. 

D. W. Schaefer, R. E. J. Sears, and J. S. Waugh. Second virial coefficients of the Kerr effect in methyl chloride, methyl fluoride and fluoroform. J. Chem. Phys., 53 2127-2128 (1970). 

Fernandez et al calculated the frequency dependent interaction-induced second hyperpolarizability of two argon atoms. Subsequently, they evaluated the dielectric, the refractivity, the Kerr and the hyperpolarizability second virial coefficients. They obtained the interaction-induced mean and the anisotropy of the dipole polarizability and the mean second hyperpolarizability of Ai2 in the range of internuclear separations defined by 5 < R/ao < 30 at the CCSD level of theory, keeping the ten innermost MO frozen. They tested several basis sets at the experimental bond length of the argon dimer. Their final choice for the calculations was a d-aug-cc-pVTZ-33211 basis. 

The low temperature refractive properties of the He gas have not been studied extensively. However, the second virial Kerr coefficient can be related to the zeroth moment of the polarized Raman spectrum, and thus deduced from the Raman experiment. For the helium gas at the liquid nitrogen temperature the experiment gives 1.46 a.u.416, the full quantum calculation 1.45328, while the classical result computed according to Eq. (1-260) gives 1.63 328. This shows that also for the Kerr effect the quantum corrections are important. A systematic study of these corrections and of the convergence of the semiclassical expansion has not been reported thus far, even though all necessary expressions are derived328. 

Measurements. The anisotropy of the pair polarizability has been determined from three types of measurements depolarized CILS spectra, pressure dependent depolarization ratios, and second virial Kerr coefficients. 

Empirical models of the induced anisotropy have also been obtained from measurements of the pressure- and field-induced optical birefringence (Kerr effect) [20]. While these are not spectroscopic procedures, we include such references here because of their significance for CILS [20, 24-26, 52, 53]. Other modeling attempts are based on measurements of depolarization ratios as a function of pressure [163, 178, 179]. In recent work satisfactory consistency of the anisotropies derived from second virial Kerr coefficients, pressure-induced depolarization ratios, and depolarized CILS has been reported [11, 80]. We note that the confusion that has existed in the early years of CILS studies is now understood to have been due to the previous lack... 

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