Recently, fluoronitrile C4F7N is regarded as a promising alternative gas for SF6, and its global warming potential (GWP) is extremely high. C4F7N has good insulation properties and a relatively low GWP, so it can be used as an insulation medium for gas-insulated switchgears. Some studies have been conducted on the decomposition pathway of C4F7N gas that may produce possible neutral molecules and free radicals, which helps understand the thermal decomposition of C4F7N. However, anions and cations will be produced under discharge conditions. In these cases, the decomposition pathway of C4F7N will be different. In this paper, the ionization decomposition pathway and the attachment decomposition pathway of C4F7N were first calculated, while the recombination processes of the cations and anions were also considered. The results can reveal the decomposition mechanism of C4F7N and the recombination mechanism of the stable products under discharge conditions. The energy changes of all the reactions were calculated, which reveals the difficulty of chemical reactions. To better investigate the formation mechanism of stable products, the partial discharge experiment was also carried out, and the decomposition products of C4F7N mixed gas were detected. Finally, the ionization energy and electron affinity energy of the stable products were also calculated, which can determine the difference in the total electronic energy between the neutral molecule and the ion. The results provide an important reference for studying the decomposition characteristics of C4F7N gas under discharge conditions from the theoretical aspect.

中文翻译：

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考虑离子参与的C4F7N气体分解路径

近年来，氟腈C4F7N被认为是一种很有前景的SF6替代气体，其全球变暖潜势（GWP）极高。C4F7N具有良好的绝缘性能和较低的GWP，因此可用作气体绝缘开关柜的绝缘介质。对可能产生中性分子和自由基的C4F7N气体的分解途径进行了一些研究，有助于了解C4F7N的热分解。但是，在放电条件下会产生阴离子和阳离子。在这些情况下，C4F7N 的分解途径会有所不同。本文首先计算了C4F7N的电离分解途径和附着分解途径，同时考虑了阳离子和阴离子的复合过程。结果可以揭示C4F7N的分解机理和放电条件下稳定产物的复合机理。计算了所有反应的能量变化，揭示了化学反应的难度。为了更好地研究稳定产物的形成机理，还进行了局部放电实验，检测了C4F7N混合气体的分解产物。最后还计算了稳定产物的电离能和电子亲和能，可以确定中性分子与离子总电子能的差异。该结果为从理论角度研究放电条件下C4F7N气体的分解特性提供了重要参考。