Rankine C D, Penfold T J
Chemistry-School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, U.K.
J Phys Chem A. 2021 May 27;125(20):4276-4293. doi: 10.1021/acs.jpca.0c11267. Epub 2021 Mar 17.
The development of high-brilliance third- and fourth-generation light sources such as synchrotrons and X-ray free-electron lasers (XFELs), the emergence of laboratory-based X-ray spectrometers, and instrumental and methodological advances in X-ray absorption (XAS) and (non)resonant emission (XES and RXES/RIXS) spectroscopies have had far-reaching effects across the natural sciences. However, new kinds of experiments, and their ever-higher resolution and data acquisition rates, have brought acutely into focus the challenge of accurately, quickly, and cost-effectively analyzing the data; a far-from-trivial task that demands detailed theoretical calculations that are capable of capturing satisfactorily the underlying physics. The past decade has seen significant advances in the theory of core-hole spectroscopies for this purpose, driven by all of the developments above and-crucially-a surge in demand. In this Perspective, we discuss the challenges of calculating core-excited states and spectra, and state-of-the-art developments in electronic structure theory, dynamics, and /machine-led approaches toward their better description.
同步加速器和X射线自由电子激光（XFEL）等高亮度第三代和第四代光源的发展、基于实验室的X射线光谱仪的出现，以及X射线吸收（XAS）和（非）共振发射（XES和RXES/RIXS）光谱学在仪器和方法上的进步，对整个自然科学产生了深远影响。然而，新型实验及其不断提高的分辨率和数据采集速率，使准确、快速且经济高效地分析数据这一挑战成为焦点；这是一项绝非轻而易举的任务，需要能够令人满意地捕捉基础物理的详细理论计算。受上述所有发展以及关键的需求激增推动，在过去十年中，为此目的的芯孔光谱学理论取得了重大进展。在这篇观点文章中，我们讨论了计算芯激发态和光谱的挑战，以及电子结构理论、动力学和以机器学习为主导的方法在更好描述它们方面的最新进展。
