Microscopic dynamics and structure of liquid⁷Li

We report an inelastic neutron scattering (INS) experiment on liquid 7 Li at 470 K, 526 K and 574 K using thermal neutrons. Fully corrected structure factors S( kappa , omega ) were obtained. We have assessed the quality of the data by means of the first frequency moment of S( kappa , omega ) and by the detailed balance condition. The coherent dynamic structure factor S c ( kappa , omega ) and the incoherent dynamic structure factor S s ( kappa , omega ) were separated by fitting models. We compare the data for S s ( kappa , omega ) at small kappa with several models using no adjustable parameters. The Lovesey model for S s ( kappa , omega ) gives very good agreement with the experimental data at all three temperatures. S s ( kappa , omega ) is not well described by the predictions from simple diffusion, mode-coupling theory or the model of Nelkin-Ghatak. The Lovesey model also gives the best agreement with the data when we fit one parameter.