Electronic structure, X-ray absorption, and magnetic circular dichroism (XMCD) spectra in the CoFeMnSi Heusler alloy were studied from first principles. Fully relativistic Dirac linear muffin-tin orbital band structure method was implemented with various exchange–correlation functionals tested. The supercell approach was used to study the influence of intersite disorder, at the levels of 6.25%, 12.5%, and 25% within transition metal sites, on the XMCD spectra at [Formula: see text] edges and spin polarization (SP) at the Fermi level. It is found that most sensitive to Fe–Mn and Co–Fe disorder are XMCD spectra at [Formula: see text] edges of Fe, while the sensitivity decreases from Mn to Co. It is shown that magnetic moments estimated with the use of magneto-optical (MO) sum rules agree with the ab initio calculated ones to within [Formula: see text], [Formula: see text], and [Formula: see text], for Co, Fe, and Mn, respectively. The calculated SP decreases from 99% for ordered CoFeMnSi alloy, to 96% upon 25% Co–Fe disorder, to 83% for Fe–Mn disorder, and to 42% in the case of Co–Mn disorder. The calculated spectra agree well with the available experimental data. The rich XMCD spectral structures are predicted from first principles at Fe, Co, Mn and Si [Formula: see text] edges.

中文翻译：

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位间无序对CoFeMnSi Heusler合金电子结构和X射线磁圆二色性影响的第一性原理计算

从第一原理研究了 CoFeMnSi Heusler 合金中的电子结构、X 射线吸收和磁圆二色性 (XMCD) 光谱。完全相对论的狄拉克线性松饼-锡轨道带结构方法实施了各种交换相关泛函测试。超晶胞方法用于研究过渡金属位点内 6.25%、12.5% 和 25% 水平的位间无序对 [公式：见文本] 边缘处的 XMCD 光谱和自旋极化 (SP) 处的影响费米能级。发现对 Fe-Mn 和 Co-Fe 无序最敏感的是 XMCD 光谱在 Fe 的 [公式：见正文] 边缘，而灵敏度从 Mn 到 Co 降低。表明使用磁电机估计的磁矩-光学 (MO) 和规则与从头算计算的规则一致 [公式：见正文]、[公式：见正文]和 [公式：见正文]，分别用于 Co、Fe 和 Mn。计算的 SP 从有序 CoFeMnSi 合金的 99% 下降到 25% Co-Fe 无序时的 96%，Fe-Mn 无序时的 83%，以及 Co-Mn 无序时的 42%。计算的光谱与可用的实验数据非常吻合。丰富的 XMCD 光谱结构是根据 Fe、Co、Mn 和 Si [公式：见文本] 边缘的第一原理预测的。