Metal-nonmetal transition in dense fluid hydrogen

The density dependence of the fluid structure and electrical resistivity of dense fluid hydrogen are studied along an isotherm of T=10(4) K using a density-functional theory for an electron-proton binary mixture. A metal-nonmetal (M-NM) transition is estimated to occur around the dimensionless density value of r(s)=2.19. The electrical resistivity rapidly increases around this value with a decrease in the hydrogen density. Simultaneously, the density dependence of the fluid structure reveals a significant jump near the M-NM transition. The character of the effective interaction potential between protons is qualitatively changed after the M-NM transition. The pressure variation suggests that the M-NM transition is a discontinuous phase transition under coexistence conditions with regard to the phase equilibrium between the metal and the nonmetal phases.