FIRST-PRINCIPLES MOLECULAR-DYNAMICS SIMULATION OF EXPANDED LIQUID RUBIDIUM

The structural and electronic properties of expanded liquid rubidium a re studied at 350 K, near the triple point, and 1400 K by means of a f irst-principles molecular-dynamics (MD) simulation, where the Kohn-Sha m energy functional is minimized for each ionic configuration of the M D step using the preconditioned conjugate-gradient method. The results for the static structure at both temperatures and the diffusion coeff icient near the triple point are in good agreement with experiments. W hile near the triple point the electron density rho(r) spreads over wh ole space, at high temperature rho(r) tends to localize due to a large spatial fluctuation of atomic density. The electron-ion correlation f unction is calculated using rho(r) and its temperature dependence is d iscussed.