The metal-nonmetal transition of liquid phosphorus by ab initio molecular-dynamics simulations

We have carried out ab initio molecular-dynamics simulations for liquid phosphorus under high temperature and high pressure in order to investigate the microscopic mechanism of the recently observed liquid-liquid phase transition of liquid phosphorus. We have successfully shown by our simulation that the structural phase transition with increasing pressure corresponds to the structural change from the molecular liquid composed of stable tetrahedral P-4 molecules to the polymeric liquid with complex network structure and that the calculated structure factors are in good agreement with those obtained by the x-ray diffraction experiments. It is also found from our calculated electronic structure that this structural change gives rise to the nonmetal-metal transition, which is the transition from the nonmetallic molecular liquid to the metallic polymeric liquid.