First-principles molecular-dynamics simulation of liquid rubidium under high pressures

Abstract

The effects of compression on the structural and electronic properties of liquid rubidium are studied along the melting curve by means of a first-principles molecular-dynamics simulation. It is shown that the calculated pair distribution functions g(r) are in good agreement with the experimental results for a wide range of pressures; the liquid rubidium is compressed uniformly at 2.5 GPa, and there exist some deviations from the uniform compression at 6.1 GPa. This structural change to a denser state is related to an electronic s-d transition in the liquid state. It is found that, near the triple point, the electronic density of states consists mostly of the s component and, with increasing pressure, the s component decreases gradually over a wide range of energy, and the d component near the Fermi level increases. @S0163-1829~97!06509-0#