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Analyzing Melts and Fluids from Ab Initio Molecular Dynamics Simulations with the UMD Package
Published on: September 17, 2021
First-principles molecular-dynamics equation of state of liquid to dense plasma iron
Augustin Blanchet1, François Soubiran1, Marc Torrent1
1Université Paris-Saclay, CEA-DAM-DIF, F-91297 Arpajon, France and , CEA, Laboratoire Matière en conditions extrêmes, 91680 Bruyères-le-Châtel, France.
Abstract:
We computed the equation of state of iron using extended first-principles molecular dynamics simulations, ranging from 7.874g/cm^{3} and 5500 K up to 47.2g/cm^{3} and 10^{9}K. We compared the principal Hugoniot curve with semiempirical models, average atom-based model predictions, and shock experiment results. We derived the Helmholtz free energy and the entropy via thermodynamic integration along isochores. We explore the ionization processes at play along the Hugoniot curve by analyzing the evolution of the electronic densities of states in the gigabar regime.
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