Ab initio simulation of the equation of state and kinetics of shocked water

摘要

We report herein first principles simulations of water under shock loading and the chemical reactivity under these hot, compressed conditions. Using a recently developed simulation techniquefor shock compression, we observe that water achieves chemical equilibrium in less than 2 ps for all shock conditions studied. We make comparison to the experimental results for the Hugoniotpressure and density final states. Our simulations show that decomposition occurs through thereversible reaction H_2O→H~++OHˉ, in agreement with experiment. Near the approximateintersection of the Hugoniot and the Neptune isentrope, we observe high concentrations of chargedspecies that contribute electronic states near the band gap.