2025-06-24 オークリッジ国立研究所（ORNL）
The melting point of lithium chloride can be accurately predicted from simulations by converting liquid salt into a gas (top) and solid crystal into a network of springs (bottom). Credit: Luke Gibson/ORNL, U.S. Dept. of Energy
＜関連情報＞
- https://www.ornl.gov/news/quantum-precision-reached-modeling-molten-salt-behavior
- https://pubs.rsc.org/en/content/articlelanding/2025/sc/d4sc07253g#!divAbstract
機械学習による高速シミュレーションで化学ポテンシャルを計算し、溶融塩の熱力学的特性を正確に予測する Computing chemical potentials with machine-learning-accelerated simulations to accurately predict thermodynamic properties of molten salts
Luke D. Gibson,Rajni Chahal and Vyacheslav S. Bryantsev
Chemical Science Published:24 Jan 2025
DOI:https://doi.org/10.1039/D4SC07253G
Abstract
The successful design and deployment of next-generation nuclear technologies heavily rely on thermodynamic data for relevant molten salt systems. However, the lack of accurate force fields and efficient methods has limited the quality of thermodynamic predictions from atomistic simulations. Here we propose an efficient free energy framework for computing chemical potentials, which is the central free energy quantity behind many thermodynamic properties. We accelerate our simulations without sacrificing accuracy by using machine learning interatomic potentials trained on density functional theory (DFT) data. Using lithium chloride as our model system, we compute chemical potentials with DFT-accuracy for solid and liquid phases by transmuting ions into noninteracting particles. Notably, in the liquid phase, we demonstrate consistency whether we transmute one ion pair or the entire system into ideal gas particles. By locating the temperature where the chemical potential of solid and liquid phases cross, we predict a melting point of 880 ± 18 K for lithium chloride, which is remarkably close to the experimental value of 883 K. With this successful demonstration, we lay the foundation for high-throughput thermodynamic predictions of many properties that can be derived from the chemical potentials of the minority and majority components in molten salts.
