NbMoTaWX (X= Ti, V, Cr, Zr, Hf, Re) RHEAs的第一性原理计算基于密度泛函理论(DFT)，使用MS的CASTEP模块和Reflex模块来完成。采用SQS法建立晶体模型，在Materials Visualizer建模模块导入Nb单质晶胞，在此基础上建立1×1×5的超胞模型，如图3.1所示。在这些模型中，用另外四种原子按比例随机替换Nb原子，五种原子在胞内随机分布以保证高熵合金短程无序特性。在计算过程中，采用广义梯度近似Generalized Gradient Approximation (GGA)下的Perdew Burke Ernzerhof (PBE) 泛函来描述电子-电子交换关联相互作用；采用模守恒赝势(Norm Conserving Pseudopotential)来描绘电子-离子的相互关系；采用BFGS算法来求解薛定谔方程。

The first principle calculation of NbMoTaWX (X=Ti, V, Cr, Zr, Hf, Re) RHEAs is based on the density functional theory (DFT) and is completed using the CASTEP module and Reflex module of MS. The crystal model is established by SQS method, and Nb single crystal cell is imported into the Materials Visualizer modeling module, on this basis, 1 × one × 5, as shown in Figure 3.1. In these models, Nb atoms are randomly replaced by four other atoms in proportion, and five atoms are randomly distributed in the cell to ensure the short-range disorder characteristics of the high entropy alloy. In the calculation process, the Perdew Burke Ernzerhof (PBE) functional under the generalized gradient approximation (GGA) is used to describe the electron-electron exchange correlation interaction; The relationship between electrons and ions is described by using Norm Conserving Pseudopotential; Using BFGS algorithm to solve Schrodinger equation