Structural and electronic properties of liquid rubidium

Using first-principle molecular-dynamics (MD) calculations, the structural and electronic properties of liquid Rb are studied along the liquid–vapor coexistence curve and along the melting curve. In both cases, the calculated pair distribution functions g(r) are in good agreement with the experimental results. Concerning the electronic properties, along the liquid–vapor coexistence curve, we study them at 350 K, the triple point, and 1400 K: near the triple point, there is no significant deviation in the electronic density of states; at the higher temperature, the deviation arises from the effects of the decreasing density and of the random potential due to the large fluctuation in the atomic configuration. Along the melting curve, liquid Rb 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. In the electronic density of states, with increasing pressure, the s component decreases gradually over a wide range of energy, and the d component near the Fermi level increases.