Abstract—

The theoretical basis of X-ray absorption spectra beyond the Fe K-edge in the pre-edge region is constructed, and algorithms for using it to quantitatively analyze experimental X-ray near edge spectroscopy (XANES) spectra are described. Within the framework of the ab initio approach of ligand field theory, 60 theoretical spectra or more for Fe with different coordination numbers, oxidation state, and interatomic distances between the central atom and the nearest O atoms are calculated. Various machine learning (ML) methods for solving problems of determining the oxidation state of Fe and coordination number by means of the obtained spectra are used. The quality of the models are estimated using the Leave-One-Out method, the determination accuracy for the oxidation state is 100%; the determination accuracy for the coordination number is 75% in the case of predictions using the entire dataset and 96 and 68% for datasets with fixed oxidation state of Fe +2 and +3, respectively.

中文翻译：

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配体场理论在非晶系统X射线吸收光谱前缘结构模拟中的应用

摘要-

Fe K以外的X射线吸收光谱的理论基础构造了前边缘区域中的边缘，并描述了用于定量分析实验性X射线近边缘光谱（XANES）光谱的算法。在配体场论从头算方法的框架内，计算了60个或更多具有不同配位数，氧化态以及中心原子与最接近的O原子之间的原子间距离的Fe的理论光谱。使用各种机器学习（ML）方法来解决通过获得的光谱确定Fe的氧化态和配位数的问题。模型的质量采用“留一法”估算，氧化态的测定准确度为100％；