CROSSOVER FROM HYDRODYNAMIC TO ATOMIC DIFFUSION IN LIQUID SELENIUM - A MOLECULAR-DYNAMICS STUDY

A molecular-dynamics (MD) study on a model of liquid selenium is presented. The model assumes the existence of linear chains with the required structural and force constant data obtained from experimental data, lattice dynamics and first-principles calculations. The computed properties show an excellent agreement with reported structure factor and density-of-states data. The analysis of the incoherent scattering function evidences the presence of strong, space-dependent effects which are a marked signature of the crossover between hydrodynamic (centre of mass) and atomic diffusion.