Collective excitations in liquid rubidium

Abstract

The dynamical structure factor S(q,ω) for liquid rubidium obtained from recent neutron inelastic scattering experiments as well as from molecular dynamics calculations has been analyzed on the basis of Mori's memory-function approach. It has been found that the double Gaussian memory function with two distinct relaxation times gives an excellent representation of the experimental data on S(q,ω) in the range of momentum transfer 0.174-2.750 ÅA⁻¹. For q≥2.750 Å⁻¹, both one- and two-relaxation-time Gaussian models reproduce the experimental data very well.