We present an ab initio theoretical method to calculate the resonant Auger spectrum in the presence of ultrafast dissociation. The method is demonstrated by deriving the L-VV resonant Auger spectrum mediated by the 2p_3/2⁻¹σ* resonance in HCl, where the electronic Auger decay and nuclear dissociation occur on the same time scale. The Auger decay rates are calculated within the one-center approximation and are shown to vary significantly with the inter-nuclear distance. A quantum-mechanical description of dissociation is effectuated by propagating the corresponding Franck–Condon factors. The calculated profiles of Auger spectral lines resemble those of atomic Auger decay but here the characteristic tails extend towards lower electron kinetic energies, which reflect specific features of the potential energy curves. The presented method can describe the resonant Auger spectrum for an arbitrary speed of dissociation and simplifies to known approximations in the limiting cases.

中文翻译：

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HCl 中超快解离 2p3/2−1σ* 共振的 Ab initio 俄歇光谱


我们提出了一种从头到尾的理论方法来计算存在超快解离下的共振俄歇谱。该方法通过推导由 HCl 中 2p_3/2⁻¹σ* 共振介导的 L-VV 共振俄歇谱来证明，其中电子俄歇衰变和核解离发生在同一时间尺度上。俄歇衰变率是在单中心近似值内计算的，并且显示随核间距离的变化而显着变化。解离的量子力学描述是通过传播相应的 Franck-Condon 因子来实现的。俄歇谱线的计算曲线类似于原子俄歇衰变的曲线，但这里的特征尾部延伸到较低的电子动能，这反映了势能曲线的特定特征。所提出的方法可以描述任意解离速度的谐振俄歇谱，并在极限情况下简化为已知的近似值。