Yukawa-Friedel-tail pair potentials for warm dense matter applications

Area of Science:

• Plasma Physics
• Computational Materials Science
• Statistical Mechanics

Background:

• Accurate equations of state (EOS) and transport properties are crucial for simulating warm dense matter (WDM).
• Molecular dynamics (MD) simulations require accurate interatomic potentials, often derived from computationally expensive methods like N-ion DFT-MD.
• The neutral-pseudoatom (NPA) approach offers a computationally cheaper alternative for obtaining pair potentials but has limitations.

Purpose of the Study:

• To develop a computationally efficient and accurate analytic model for pair potentials in WDM.
• To provide a physically meaningful model that can be extrapolated for various particle separations.
• To enable large-scale simulations of multispecies WDM by improving potential calculations.

Main Methods:

• Proposed a novel analytic pair potential model: the Yukawa form with a thermally damped Friedel tail (YFT).
• Validated the YFT model by fitting it to pair potentials derived from the neutral-pseudoatom (NPA) approach.
• Compared YFT model performance against nonparametric force-matched potentials from N-ion DFT-MD.

Main Results:

• The YFT model accurately reproduces NPA and force-matched potentials across a wide range of conditions.
• The YFT model demonstrates excellent agreement with existing methods for WDM systems.
• The model provides reliable extrapolations for both small and large interparticle distances.

Conclusions:

• The YFT model offers a significant improvement in computational efficiency for WDM simulations.
• This physically grounded analytic potential facilitates accurate and large-scale simulations of WDM, including plasma mixtures.
• The YFT model is a valuable tool for advancing research in high-energy-density physics.