Equilibrium and Non-Equilibrium Orbital-Free Molecuar Dynamics Simulations at Extreme Conditions
Year: 2013
Type: article
Abstract: Large-scale molecular dynamics (MD) simulations in an orbital-free (OF) densityfunctional theory (DFT) formulation have been performed for pure and mixed species over a broad range of temperatures and densities that includes the warm, dense matter regime.A finite-temperature Thomas-Fermi-Dirac form with a local-density exchangecorrelation potential and a regularized electron-ion interaction represents the quantum nature of the electrons.In particular, we examine the efficacy of the OFMD approach as an effective bridge between Kohn-Sham DFT MD at low temperatures and simple, fullyionized plasma models at high temperatures.Comparisons against intermediate-range constructions such as the Yukawa and one-component plasmas are also made.To this end, we treat a variety of systems, ranging from light to heavy elements, from which lithium hydride, including illustrations from the shock Hugoniot and mass transport properties (diffusion, viscosity), serves as a representative example.In addition, nonequilibrium simulations, both with OFMD and classical Yukawa MD, of the interpenetration of two components at an interface are presented, with relevance to such applications as inertial confinement fusion.
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: U.S. Department of Energy
OpenAlex ID: W158359730