Schio Luca, Li Cui, Monti Susanna, Salén Peter, Yatsyna Vasyl, Feifel Raimund, Alagia Michele, Richter Robert, Falcinelli Stefano, Stranges Stefano, Zhaunerchyk Vitali, Carravetta Vincenzo
Dipartimento di Chimica, Università Sapienza, Roma, I-00185, Italy.
Phys Chem Chem Phys. 2015 Apr 14;17(14):9040-8. doi: 10.1039/c4cp05896h. Epub 2015 Mar 10.
The electronic structure of nitrosyl chloride (ClNO) has been investigated in the gas phase by X-ray Photoelectron (XPS) and Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy at the Cl 2p, Cl 2s, N 1s and O 1s edges in a combined experimental and theoretical study. The theoretical calculations at different levels of approximation predict ionization potential values in good agreement with the experimental data and allow us to assign the main features of the absorption spectra. An unexpected failure of the density functional model is, however, observed in the calculation of the Cl 2s binding energy, which is related to a large self-interaction error. Largely different photoabsorption cross-section patterns are experimentally observed in core excitations from the investigated quantum shells (n = 1, 2). This finding is confirmed by the oscillator strength distributions calculated at different absorption edges; in the case of the n = 2 shell the bands below the threshold are extremely weak and most of the absorption intensity is due to excitations in the continuum.
在一项结合实验与理论的研究中，利用X射线光电子能谱（XPS）和近边X射线吸收精细结构谱（NEXAFS），在Cl 2p、Cl 2s、N 1s和O 1s边对气相中的亚硝酰氯（ClNO）的电子结构进行了研究。不同近似水平的理论计算预测的电离势值与实验数据吻合良好，并使我们能够确定吸收光谱的主要特征。然而，在计算Cl 2s结合能时，观察到密度泛函模型出现了意外的失效，这与较大的自相互作用误差有关。在来自所研究量子壳层（n = 1, 2）的芯激发中，实验观察到了大不相同的光吸收截面模式。这一发现通过在不同吸收边计算的振子强度分布得到了证实；在n = 2壳层的情况下，阈值以下的能带极其微弱，大部分吸收强度归因于连续态中的激发。
