Yukawa Friedel-Tail pair potentials for warm dense matter applications

Abstract

Accurate equations of state (EOS) and plasma transport properties are essential for numerical simulations of warm dense matter encountered in many high-energy-density situations. Molecular dynamics (MD) is a simulation method that generates EOS and transport data using an externally provided potential to dynamically evolve the particles without further reference to the electrons. To minimize computational cost, pair potentials needed in MD may be obtained from the neutral-pseudoatom (NPA) approach, a form of single-ion density functional theory (DFT), where many-ion effects are included via ion-ion correlation functionals. Standard $N$-ion DFT-MD provides pair potentials via the force matching technique but at much greater computational cost. Here we propose a simple analytic model for pair potentials with physically meaningful parameters based on a Yukawa form with a thermally damped Friedel tail (YFT) applicable to systems containing free electrons. The YFT model accurately fits NPA pair potentials or the non-parametric force-matched potentials from $N$-ion DFT-MD, showing excellent agreement for a wide range of conditions. The YFT form provides accurate extrapolations of the NPA or force-matched potentials for small and large particle separations within a physical model. Our method can be adopted to treat plasma mixtures, allowing for large-scale simulations of multi-species warm dense matter.

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References in corpus (11)

• A Spectral Analysis Method for Automated Generation of Quantum-Accurate Interatomic Potentials
• Potfit: effective potentials from ab-initio data
• All-Electron Path Integral Monte Carlo Simulations of Warm Dense Matter: Application to Water and Carbon Plasmas
• Effective potentials for quasicrystals from ab-initio data
• An integral equation model for warm and hot dense mixtures
• Isochoric, isobaric and ultrafast conductivities of aluminum, lithium and carbon in the warm dense matter (WDM) regime
• Efficacy of the Radial Pair Potential Approximation for Molecular Dynamics Simulations of Dense Plasmas
• The ionization of carbon at 10-100 times the diamond density and in the 10${}^6$ K temperature range
• Correlation functions in electron-electron and electron-hole double quantum wells: Temperature, density and barrier-width dependence
• Evidence for multiple Liquid-liquid phase transitions in carbon, and the Friedel-ordering of its liquid state
• Simple pair-potentials and pseudo-potentials for warm-dense matter and general applications

Cited by in corpus (1)

• Transferable Interatomic Potentials for Aluminum from Ambient Conditions to Warm Dense Matter