Fragmentation processes following C $1s\to \text{lowest}$ unoccupied molecular orbital core excitations in ${\mathrm{CF}}_4$ have been analyzed on the ground of the angular distribution of the ${\mathrm{CF}}_3^{+}$ emitted fragments by means of Auger electron-photoion coincidences. Different time scales have been enlightened, which correspond to either ultrafast fragmentation, on the few-femtosecond scale, where the molecule has no time to rotate and the fragments are emitted according to the maintained orientation of the core-excited species, or dissociation after resonant Auger decay, where the molecule still keeps some memory of the excitation process before reassuming random orientation. Potential energy surfaces of the ground, core-excited, and final states have been calculated at the ab initio level, which show the dissociative nature of the neutral excited state, leading to ultrafast dissociation, as well as the also dissociative nature of some of the final ionic states reached after resonant Auger decay, yielding the same fragments on a much longer time scale.

中文翻译：

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两个内部时钟在核激发CF4分解动力学中的不同时间尺度

C之后的碎片过程 $\mathrm{1个}s\to \text{最低}$ 分子轨道中未占据的核激发 ${\mathrm{碳纤维}}_4$ 已经基于 ${\mathrm{碳纤维}}_3^{+}$通过俄歇电子-光子巧合发射出碎片。启迪了不同的时间尺度，这对应于几飞秒尺度上的超快速断裂，其中分子没有时间旋转，并且根据核激发物质的维持方向发射碎片，或者在共振后解离俄歇衰变，在重新假定随机取向之前，分子仍保留对激发过程的某种记忆。从头算起就已经计算出了基态，核心激发态和最终态的势能面 能级，显示中性激发态的离解性质，导致超快离解，以及共振俄歇衰变后达到的某些最终离子态的离解性质，在更长的时间尺度上产生相同的碎片。