Polymeric liquid of phosphorus at high pressure: First-principles molecular-dynamics simulations

Constant-pressure first-principles molecular-dynamics simulations were carried out to study structural and electronic properties of the polymeric phase of liquid phosphorus at high pressures. It is found that, around 1 GPa, atoms are connected by covalent bonds by p electrons and accompany a Peierls distortion as in liquid arsenic. This liquid structure reflects the rhombohedral (A7) structure of crystalline phosphorus in local atomic configurations. Further compression increases the number of the first nearest neighbors and reduces the Peierls distortion. It is considered that the reduction of the Peierls distortion in the liquid phase is closely related to the transition from the A7 to simple cubic structures in crystalline phases. The characteristics of liquid phosphorus around 25 GPa and over are similar to those of liquid antimony and bismuth.