Electron-ion correlation in liquid metals from first principles: Liquid Mg and liquid Bi

We present a theoretical determination of electron-ion pair correlation functions gie in liquid Mg and liquid Bi, two systems with widely different electronic and cohesive properties. Our calculations are based on first-principles molecular-dynamics simulations, which provide an accurate and mutually consistent description of the atomic and electronic structures of these systems. Our results show that gie exhibits substantially different features in Mg and Bi liquids. For liquid Mg, gie clearly reflects the delocalization of the valence atomic charge related to metallic bond formation. In the case of Bi, instead, the spherical average implicit in gie does not allow it to reveal the existence of transient directional bonds which are an important feature of the charge density in this liquid.