Multicomponent mutual diffusion in the warm, dense matter regime.

Area of Science:

• Computational Physics
• Materials Science
• Chemical Engineering

Background:

• Binary mixture mass transport is well-studied, but complex multicomponent systems, especially in warm, dense matter, are less understood.
• Accurate diffusion coefficients are crucial for modeling phenomena in high-energy-density physics, astrophysics, and materials science.

Purpose of the Study:

• To present the formulation, simulations, and results for multicomponent mutual diffusion coefficients in the warm, dense matter regime.
• To explicitly examine ternary systems and their diffusion behavior.
• To evaluate the efficacy of various approximations in diffusion calculations.

Main Methods:

• Utilized the Maxwell-Stefan formulation to relate diffusion to chemical potential gradients.
• Employed molecular dynamics (MD) simulations, including Born-Oppenheimer and classical MD with Yukawa potentials.
• Generated particle trajectories to compute autocorrelation functions (ACFs) and Onsager coefficients.

Main Results:

• Calculated multicomponent mutual diffusion coefficients for various ternary mixtures (e.g., D-Li-C, D-Li-Cu, H-C-Ag).
• Examined diffusion trends as a function of density, temperature, and number concentration.
• Determined center-of-mass coefficients via a similarity transformation of ACFs.

Conclusions:

• The study provides crucial data on multicomponent diffusion in warm, dense matter.
• The employed methods offer a robust framework for investigating complex fluid mixtures.
• Findings contribute to a deeper understanding of mass transport in extreme conditions.