Intermolecular interaction effect on the line-shape of hyper-Rayleigh light scattering by molecular liquids

Abstract

Scattering on molecules, correlated in regions of short-range quasi-ordering, is analysed with regard to its effect on the spectrum of hyper-Rayleigh light-scattering by molecular liquids. The general form of S ^2ω _c(ℋ, Δω) derived using spherical tensors and expanding the orientational-positional-time pair correlation function in Wigner functions, is discussed on the assumption that Vineyard's [22] approximation can be applied to calculate G _c[τ₁(t), τ₂(0)]. Successive terms of the expansion are calculated assuming dipole-dipole interaction energy as predominant in the total molecular electric multipole interaction energy. In the present approximation the contribution from scattering on correlated molecules is shown to be given by the difference of two Lorentz lines, whose maxima depend on the magnitude of the interactions. The integral intensities, calculated from the formulae derived here, are in agreement with those of the literature.