Ab initiocalculation of density dependence of liquid-Na properties

We have performed ab initio quantum-mechanical calculations of the Hellmann-Feynman forces in liquid Na, which were used in a molecular-dynamics simulation without recourse to Car-Parrinello methods. The diffusion coefficient (D) and pressure (P) were obtained as a function of the temperature (T) and volume (V). Three simple formulas relating D to T, D to V, and P to V were found to be obeyed.