In this paper, we investigate HNCO by resonant and nonresonant Auger electron spectroscopy at the K-edges of carbon, nitrogen, and oxygen, employing soft X-ray synchrotron radiation. In comparison with the isosteric but linear CO₂ molecule, spectra of the bent HNCO molecule are similar but more complex due to its reduced symmetry, wherein the degeneracy of the π-orbitals is lifted. Resonant Auger electron spectra are presented at different photon energies over the first core-excited 1s → 10a′ resonance. All Auger electron spectra are assigned based on ab initio configuration interaction computations combined with the one-center approximation for Auger intensities and moment theory to consider vibrational motion. The calculated spectra were scaled by a newly introduced energy scaling factor, and generally, good agreement is found between experiment and theory for normal as well as resonant Auger electron spectra. A comparison of resonant Auger spectra with nonresonant Auger structures shows a slight broadening as well as a shift of the former spectra between −8 and −9 eV due to the spectating electron. Since HNCO is a small molecule and contains the four most abundant atoms of organic molecules, the reported Auger electron decay spectra will provide a benchmark for further theoretical approaches in the computation of core electron spectra.

中文翻译：

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HNCO异氰酸的正则和共振俄歇谱

在本文中，我们使用软X射线同步加速器辐射，通过共振和非共振俄歇电子能谱研究了碳，氮和氧的K边缘处的HNCO。与等排的但线性的CO ₂分子相比，弯曲的HNCO分子的光谱相似但由于其对称性降低而更加复杂，其中提升了π轨道的简并性。在第一个磁芯激发的1s→10a'共振中，在不同的光子能量下呈现共振俄歇电子能谱。所有的俄歇电子能谱均基于从头算起进行分配配置相互作用计算与俄歇强度的一中心近似和矩量理论相结合，以考虑振动运动。计算出的光谱通过新引入的能量比例因子进行比例缩放，通常，在实验和理论之间可以找到对于正常以及共振俄歇电子光谱的良好一致性。共振俄歇光谱与非共振俄歇结构的比较显示，由于电子的存在，前者的光谱在-8 eV至-9 eV之间略有加宽和移动。由于HNCO是一个小分子，并且包含有机分子中四个最丰富的原子，因此报道的俄歇电子衰变光谱将为核心电子光谱的计算中的进一步理论方法提供基准。