Liquid xenon as an ideal probe for many-body effects in impulsive Raman scattering

Abstract

The molecular origins of the two-dimensional Raman spectrum of an atomic liquid. I. Molecular dynamics simulationThe collision induced effects in the third-order Raman response of liquid xenon have been studied both experimentally and theoretically. The effect of electron cloud overlap on the polarizability of xenon dimers was studied using accurate time-dependent density functional theory calculations. The dimer polarizabilities were used to fit parameters in a direct reaction field model that can be generalized to condensed phase systems. This model was employed in molecular dynamics simulations in order to calculate the impulsive Raman response of liquid xenon. Excellent agreement is found between the shape of the calculated and the measured anisotropic part of the response. The shape of this response is little affected by the electron overlap effects, but the intensity is strongly influenced by it. The shape of the isotropic response is predicted to be strongly dependent on electron overlap effects.

Rattling the cage: Micro- to mesoscopic structure in liquids as simple as argon and as complicated as water

“…The logical next step then is to study molecules with a centre of inversion (e.g., methane) or even atoms. [105][106][107] We have studied the noble-gas liquids of argon, krypton, and xenon under the initial assumption that the dynamics would be extremely simple. [73] OKE spectroscopy (as well as anisotropic Raman scattering) is sensitive to rotation of the polarizability tensor.…”

Universal nonexponential relaxation: Complex dynamics in simple liquids

“…Ultrafast optical Kerreffect ͑OKE͒ spectroscopy probes many-body interactions and is established as a powerful probe of structural relaxation in both complex and simple liquids. [5][6][7][8][9][10][11][12] However, no detailed OKE study of the noble-gas liquids exists. OKE spectroscopy ͑the time-domain variant of Raman spectroscopy͒ measures the time-derivative of the two-point time-correlation of the anisotropic part of the many-body polarizability tensor.…”

“…Detailed analysis is not straightforward and has not been made previously. 10,13 The Bucaro-Litovitz function was derived as a model of the Raman spectrum for these liquids 14 but is based on ͑head-on͒ collisions in the gas phase for a Lennard-Jones fluid and is a poor model of this response failing, particularly, to reproduce a͒ Electronic mail: david.turton@phys.strath.ac.uk. Debye the broad nature of the spectrum.…”

Density-dependent photoabsorption cross sections of atomic Xe

“…However, monatomic gases like xenon are known to have a Raman spectrum at higher densities due to a collisioninduced anisotropy of the polarizability tensor of pairs of atoms, consisting of nearly symmetric, nearly exponential continua on the Stokes and anti-Stokes sides. [17] This makes atomic liquid such as liquid xenon excellent probes for studies of intermolecular interactions and motions. [18] Liquid xenon was used to investigate the effects of overlapping electron clouds and dipole induced-dipole interactions on the optical response.…”