Dynamics of liquid lithium atoms: Time scales and dynamic correlation functions

Abstract

© 2020 Polish Academy of Sciences. All rights reserved. Memory functions of the relaxation process of the density fluctuations of the lithium melt near the melting point on the basis of molecular dynamics data are calculated. It is established that the memory functions of the first four orders for the range of wave numbers corresponding to microscopic spatial scales are characterized by oscillating behavior. The frequency characteristics of the dynamic structure factor for a wide range of wave numbers are calculated. The convergence of the relaxation parameters Δ4(k) and Δ5(k) for the range of wave numbers from the hydrodynamic regime (k → 0) to the values of k higher than the boundary of the first pseudo-Brillouin zone (for k ≈ 0:87km) are detected. The characteristic time scales of the process of structural relaxation of the density fluctuations are determined.