title: Evidence for a first-order liquid-liquid transition in high-pressure hydrogen from ab initio simulations.
abstract: Using quantum simulation techniques based on either density functional theory or quantum Monte Carlo, we find clear evidence of a first-order transition in liquid hydrogen, between a low conductivity molecular state and a high conductivity atomic state. Using the temperature dependence of the discontinuity in the electronic conductivity, we estimate the critical point of the transition at temperatures near 2,000 K and pressures near 120 GPa. Furthermore, we have determined the melting curve of molecular hydrogen up to pressures of 200 GPa, finding a reentrant melting line. The melting line crosses the metalization line at 700 K and 220 GPa using density functional energetics and at 550 K and 290 GPa using quantum Monte Carlo energetics.
authors.affiliation: Physics Department, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Morales
authors.forename: Carlo
authors.initials: C
authors.lastname: Pierleoni
authors.forename: Eric
authors.initials: E
authors.lastname: Schwegler
authors.forename: D M
authors.initials: DM
authors.lastname: Ceperley