Density functional theory (DFT) calculations show that it is essential to consider the magnetic contribution to the total energy for the end-members of the σ phase. A more straightforward method to use the DFT results in a CALPHAD (Calculation of phase diagrams) description has been applied in the present work. It was found that only the results from DFT calculations considering spin-polarization are necessary to obtain a reliable description of the σ phase. The benefits of this method are: the DFT calculation work can be reduced and the CALPHAD description of the magnetic contribution is more reliable. A revised thermodynamic description of the Co-Cr system is presented which gives improved agreement with experimental phase boundary data for the σ phase.

中文翻译：

---

Co Cr 体系中拓扑密堆积 σ 相的热力学分析

密度泛函理论 (DFT) 计算表明，必须考虑磁性对 σ 相端元总能量的贡献。在 CALPHAD（相图计算）描述中使用 DFT 结果的一种更直接的方法已应用于当前的工作中。发现仅需要考虑自旋极化的 DFT 计算结果才能获得 σ 相的可靠描述。这种方法的好处是：可以减少 DFT 计算工作，并且对磁贡献的 CALPHAD 描述更可靠。提出了 Co-Cr 系统的修订热力学描述，它与 σ 相的实验相界数据更加一致。