Thermodynamic evaluations and optimizations of the NaF-ZnF₂, KF-ZnF₂, RbF-ZnF₂, NaF-RbF and KF-RbF systems were determined by use of the CAlculation of PHAse Diagrams (CALPHAD) approach in this work. The subregular solution model was applied to model liquid phase, while the stoichiometric compound model was used to describe the intermediate phases. All the model parameters were evaluated on the basis of the required thermochemical and phase equilibrium data from experimental measurements in literature and theoretical predictions from first-principles method. A set of self-consistent and reliable thermodynamic database for the NaF-KF-RbF-ZnF₂ quaternary system was finally derived by merging the model parameters of relevant binary systems (model parameters of NaF-KF were adopted from the literature) based upon the Muggianu extrapolation model. The invariant reactions of ternary systems from NaF-KF-RbF-ZnF₂ were obtained according to the database. This work will provide beneficial instructions in the relevant multi-components molten salt design in industrial fields.

通过使用PHAse图的计算（CALPHAD）方法确定了NaF-ZnF ₂，KF-ZnF ₂，RbF-ZnF ₂，NaF-RbF和KF-RbF系统的热力学评估和优化。亚正规溶液模型用于液相建模，而化学计量化合物模型用于描述中间相。所有模型参数都是根据所需的热化学和相平衡数据（来自文献中的实验测量值和第一原理方法的理论预测值）进行评估的。NaF-KF-RbF-ZnF _2的一组自洽且可靠的热力学数据库通过合并相关二元系统的模型参数（从文献中采用NaF-KF的模型参数），最终基于Muggianu外推模型得出四元系统。根据数据库，从NaF-KF-RbF-ZnF ₂获得三元系统的不变反应。这项工作将为工业领域中相关的多组分熔盐设计提供有益的指导。