Interaction induced light scattering

Abstract

Several simplified models are discussed, more or less directly based upon Kirkwood's superposition approximation, currently employed in interpreting interaction induced light scattering spectra in high density simple fluids. Calculations are performed of the first two spectral moments for room temperature argon at moderate and high densities in Kirkwood's approximation using pair correlation functions from molecular dynamics and the dipole-induced-dipole pair polarizability model. Comparison with full molecular dynamics calculations indicates that at room temperature accurate zeroth and second spectral moments can be obtained using the superposition approximation and shows the limits of more simplified models in describing the density evolution of the spectral moments. The approximation is shown to work also for other induced polarizability models.