Universal Thermodynamic Interatomic Potentials (TIP) for Crystalline Materials

Forum topic · 小凯 · 2026-08-18

Summary

Free energies determine solid-state phase stability, yet computational materials discovery still relies mostly on ground-state energies because free energy calculations require expensive ensemble averages. This paper introduces the Thermodynamic Interatomic Potential (TIP), which extends an interatomic potential from its static energy to a thermodynamically consistent Gibbs free energy model. Thermodynamic responses such as entropy and volume follow automatically via differentiation with respect to temperature and pressure. The authors implement TIP[UMA] on top of the universal potential UMA, training it on free energies spanning from quasi-harmonic to molecular dynamics fidelity and calibrating it against higher-resolution calculations or experimental data. From a single evaluation, the model returns a crystal's equation of state and locates phase transitions among competing branches, including dynamically stabilized phases. Fine-tuning further extends the model to alloy solubility limits and miscibility gaps. TIP makes free energies as accessible as potential energies, opening the door to high-throughput discovery of finite-temperature phase stability. Source: arXiv:2508.08536 by Juno Nam, Bowen Deng, and Xiaochen Du.

Paper Overview

Field: Machine Learning
Authors: Juno Nam, Bowen Deng, Xiaochen Du
arXiv: 2508.08536

Abstract (English)

Free energies govern solid-state phase stability, yet computational materials discovery still relies largely on ground-state energies because free energy calculations require ensemble averages. We introduce the thermodynamic interatomic potential (TIP), which extends an interatomic potential from its static energy to a thermodynamically consistent Gibbs free energy model, with thermodynamic responses following from temperature and pressure by automatic differentiation. We implement TIP[UMA] using the universal potential UMA, train it on free energies from quasi-harmonic to molecular dynamics fidelity, and calibrate it to higher-resolution calculations or experiment. From a single evaluation, it returns the equation of state of a crystal and locates phase transitions among competing branches, including dynamically stable phases. Fine-tuning extends the model to alloy solubility limits and miscibility gaps. TIP makes free energies as accessible as potential energies, opening the door to high-throughput discovery of finite-temperature phase stability.

Key Contributions

Extends interatomic potentials from static energies to Gibbs free energy models, thermodynamically consistent by construction.
Thermodynamic responses (entropy, volume, etc.) obtained via automatic differentiation with respect to temperature and pressure.
TIP[UMA]: built on the universal potential UMA, trained on free energies from quasi-harmonic to MD-level fidelity, calibrated to higher-resolution computations or experiment.
A single evaluation yields a crystal's equation of state and locates phase transitions among competing branches, including dynamically stable phases.
Fine-tuning covers alloy solubility limits and miscibility gaps.

Significance

By making free energies as cheap to evaluate as potential energies, TIP enables high-throughput screening of finite-temperature phase stability — a long-missing capability in computational materials discovery.

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