Signal Universal Thermodynamic Interatomic Potentials for Crystalline Materials

Summary

A preprint introduces the thermodynamic interatomic potential, or TIP, which extends a machine-learned interatomic potential from static ground-state energy to a thermodynamically consistent Gibbs free-energy model. Thermodynamic responses are obtained through automatic differentiation over temperature and pressure. The authors implement TIP on top of the universal potential UMA, training it on free energies spanning quasi-harmonic to molecular-dynamics fidelity. 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 extends it to handle alloy solubility limits and miscibility gaps as well.