Formamide, a simple model bio-molecule (HCONH₂), is irradiated with high intensity, ultrashort pulses from an x-ray free electron laser. Ionic fragments resulting from photoionization and subsequent decay processes are recorded, as well as the electronic signature of the different inner shell ionization events that can take place during the x-ray pulses. The formation of double-core-hole states, where a second inner shell electron is removed before the first core hole has been refilled is observed in the electron spectra, recorded at all three sites (C, N, O) of the molecule. The individual ionization potentials are compared with results of ab initio calculations at different level of theory. Based on our results, future opportunities for advanced studies of inner-shell-induced electronic and nuclear dynamics are explored.

甲酰胺是一种简单的模型生物分子（HCONH ₂），由来自X射线自由电子激光的高强度超短脉冲辐照。记录由光电离和随后的衰减过程产生的离子碎片，以及在X射线脉冲期间可能发生的不同内壳电离事件的电子签名。在电子光谱中观察到双核孔态的形成，在该光谱中在分子的所有三个位置（C，N，O）记录了第二个内壳电子在重新填充第一个核孔之前被除去的状态。将各个电离势与从头算的结果进行比较不同理论水平的计算。根据我们的结果，探索了进一步研究内壳诱导的电子和核动力学的机会。