Distinct metallization and atomization transitions in dense liquid hydrogen

Abstract

We perform molecular dynamics simulations driven by accurate Quantum Monte Carlo forces on dense liquid hydrogen. Recently it has been reported a complete atomization transition between a mixed-atomic liquid and a completely dissociated fluid in an almost unaccessible pressure range {[\emph{Nat. Commun.} {\bf 5}, 3487 (2014)]}. Here instead, in a much more interesting pressure range, we identify a different transition between the fully molecular liquid and the mixed-atomic fluid at $\sim$ 400 GPa, with numerical evidence supporting its metallic behavior. Therefore we predict that the metallization at finite temperature occurs in this partially dissociated molecular fluid, well before the complete atomization of the liquid. At high temperature this first-order transition becomes a crossover, in very good agreement with the experimental observation. Several systematic tests supporting the quality of our large scale calculations are also reported.

References in corpus (6)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• An Efficient and Accurate Car-Parrinello-like Approach to Born-Oppenheimer Molecular Dynamics
• Nuclear Quantum Effects and Nonlocal Exchange-Correlation Functionals Applied to Liquid Hydrogen at High Pressure
• Stable liquid Hydrogen at high pressure by a novel ab-initio molecular dynamics
• Resonating valence bond wave function with molecular orbitals: Application to first-row molecules
• Unexpectedly high pressure for molecular dissociation in liquid hydrogen by a reliable electronic simulation

Cited by in corpus (4)

• Phase diagram of hydrogen and a hydrogen-helium mixture at planetary conditions by Quantum Monte Carlo simulations
• Ab-initio molecular dynamics simulation of liquid water by Quantum Monte Carlo
• Evidence for Stable Square Ice from Quantum Monte Carlo
• Toward Accurate Adsorption Energetics on Clay Surfaces