发表机构
École Polytechnique Fédérale de Lausanne（洛桑联邦理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出基于能量累积量的自由能计算方法，替代传统特殊准随机结构近似，在九元素难熔体系中可大幅降低自由能误差，还用于筛选富锂岩盐氧化物的可合成无序相，适用于任意晶格与化学体系。
AI 中文摘要
预测无序相的有限温度稳定性需要其自由能，传统上通过将特殊准随机结构（模拟随机合金的小晶胞）的能量与理想构型熵结合来近似，该近似忽略了冷却过程中形成的短程有序。本研究表明，传统近似是自由能在能量累积量无穷级数展开的第一项，高阶累积量可通过随机排列的能量估算，无需蒙特卡洛或分子动力学方法。在一个九元素难熔体系中，添加第二项累积量使自由能误差降低了约一个数量级。该展开可给出包含有序-无序转变、缺陷浓度和短程有序的相图。为验证其实用性，我们采用基础原子间势对26种元素的富锂岩盐氧化物进行筛选，以寻找富含锂渗流所需Li₄团簇的可合成无序相。该方法适用于任意晶格和化学体系，使无序相的常规筛选成为可能。
英文摘要
Predicting the finite-temperature stability of a disordered phase requires its free energy. It is traditionally approximated by combining the energy of a special quasirandom structure (a small cell mimicking a random alloy) with the ideal configurational entropy. This approximation neglects the short-range order that develops on cooling. In this study, we show that the conventional approximation is the first term of an infinite expansion of the free energy in energy cumulants. Higher-order cumulants are estimated from energies of random arrangements, without Monte Carlo or molecular dynamics. In a nine-element refractory system, adding the second cumulant reduced free energy errors by about an order of magnitude. The expansion gives phase diagrams with order--disorder transitions, defect concentrations, and short-range order. To demonstrate its utility, we used a foundation interatomic potential to screen lithium-excess rocksalt oxides across 26 elements for synthesizable disordered phases rich in the Li$_4$ clusters needed for lithium percolation. The approach applies to any lattice and chemistry, and brings disordered phases within reach of routine screening.
