The liquid–liquid phase transition of liquid phosphorus studied by ab initio molecular-dynamics simulations

Abstract We have carried out ab initio molecular-dynamics simulations for liquid phosphorus under high-temperature and high-pressure in order to investigate the observed liquid–liquid phase transition of liquid phosphorus. In our simulations, the difference in ionic configuration between the low-density liquid and high-density liquid clearly appears. For the low-density liquid, tetrahedral P 4 clusters exist as isolated clusters with high stability and do not break within our simulation time. For the high-density liquid, on the other hand, no tetrahedral structure is found, but rather there exists the complex P-ion network structure. The calculated structure factors are in good agreement with the observed X-ray diffractions and their characteristic features can be explained as associated with the ionic configurations. The electronic structures can be explained on the basis of those ionic configurations.