Exploration of Entropy Pair Functional Theory

Area of Science:

• Computational materials science
• Statistical mechanics
• Thermodynamics

Background:

• Calculating excess entropy from molecular dynamics (MD) simulations is challenging.
• Traditional methods like thermodynamic integration are computationally intensive.
• Previous work showed a functional based on the pair correlation function (PCF) could estimate iron's excess entropy.

Purpose of the Study:

• To assess the general applicability of the Entropy Pair Functional Theory (EPFT) for calculating excess entropy.
• To test EPFT with various many-body interaction potentials.
• To advance towards a universal functional for entropy determination.

Main Methods:

• Applied the Entropy Pair Functional Theory (EPFT) to systems simulated with many-body potentials.
• Utilized modified embedded atom method (MEAM) potentials for Fe and Cu.
• Employed a Tersoff potential for Si.

Main Results:

• EPFT demonstrated robust performance in determining excess entropy across diverse systems.
• The approach successfully handled complex many-body interactions.
• Accurate excess entropy calculations were achieved for Fe, Cu, and Si.

Conclusions:

• EPFT is a generally applicable and robust method for calculating excess entropy in MD simulations.
• This work validates EPFT for potentials beyond simple pair potentials.
• The findings pave the way for a universal Entropy Pair Functional (EPF) for various simulations.