[Paper Review] Incorporating Gibbs free energy into interatomic potential fitting

Liangrui Wei, Yang Sun|arXiv (Cornell University)|Jan 30, 2026

High-pressure geophysics and materials0 citations

TL;DR

The paper proposes a Hamiltonian thermodynamic integration-based method to fit high-temperature Gibbs free energy data for interatomic potentials, enabling free-energy-mocused parameter fitting alongside traditional property targets.

ABSTRACT

We develop a method to fit high-temperature Gibbs free energy data for the development of interatomic potentials for atomic systems. The approach is based on Hamiltonian thermodynamic integration, enabling the identification of suitable potential parameters such that the system's free energy matches a specified target. The method can be readily combined with conventional fitting techniques for properties such as elastic tensors and liquid pair distribution functions. We validate the effectiveness of the approach using the Uhlenbeck-Ford model and embedded-atom method potentials for pure Ni phases and binary Fe1-xOx liquids under high-pressure and high-temperature conditions. Our framework provides an efficient strategy for incorporating free energy into interatomic potential fitting.

Motivation & Objective

• Motivate integrating Gibbs free energy into interatomic potential fitting for high-temperature systems.
• Develop a Hamiltonian thermodynamic integration framework to match target Gibbs free energy with potential parameters.
• Show compatibility with conventional fitting targets like elastic tensors and liquid structure.
• Validate the approach on model and real-material potentials across high-pressure/high-temperature conditions.

Proposed method

• Use Hamiltonian thermodynamic integration to connect potential parameterization with target Gibbs free energy.
• Identify potential parameters that align system free energy with a specified target.
• Combine the Gibbs-energy fitting with standard property-based fitting (e.g., elastic tensors, pair distribution functions).
• Apply the method to select potentials and validate against known models and materials.
• Iterate fitting to minimize deviation between computed and target Gibbs free energy.

Experimental results

Research questions

• RQ1 Can Gibbs free energy data be effectively incorporated into interatomic potential fitting via Hamiltonian thermodynamic integration?
• RQ2 How does Gibbs-energy-based fitting interact with conventional property-based fitting targets like elastic and structural descriptors?
• RQ3 Does the method improve transferability of potentials under high-temperature and high-pressure conditions?
• RQ4 What are the validation benchmarks for the approach on specific systems?

Key findings

• The method enables fitting potential parameters so that the system's Gibbs free energy matches a target value.
• It can be integrated with standard fitting procedures for elastic and structural properties.
• Validation on the Uhlenbeck–Ford model shows compatibility with Gibbs-energy fitting.
• Embedded-atom method (EAM) potentials for pure Ni and binary Fe1−xOx liquids were tested under high P–T to demonstrate applicability.
• The framework offers an efficient strategy for incorporating free energy into interatomic potential fitting.