Fig. 4: Sketch of the discussed processes.

All processes start with an initial X-ray photoabsorption, as depicted on the left (light yellow area). The green arrow and central green section show the wave-packet evolution, which occurs simultaneously with the AM decay (light green area). Excitation of the 1s electron A yields a wave packet (denoted as 1s⁻¹np CTTS states) that is partially localized on the metal ion (red lobes) and partially delocalized on the surrounding water molecules (blue cloud). Associated early-time AM decays will reflect the more localized wave-packet character, resulting in either the localized final states after spectator AM decay, denoted as 2p⁻²3p (red arrow), or the delocalized final states after normal AM decay, denoted as 2p⁻² (blue arrow). Later AM decays take place with the wave packet being more delocalized on the surrounding water molecules (denoted as 1s⁻¹e_delocalized, B), resulting predominantly in the 2p⁻² final states (blue arrow). Above the 1s ionization threshold, photoabsorption of the 1s electron leads to an expanding photoelectron wave packet (denoted as 1s⁻¹e, C), which again develops into 1s⁻¹e_delocalized. In the early stages, AM decay partially leads to localized 2p⁻²3p final states (red arrow, less likely) and predominantly to 2p⁻² final states. In the later stages, the decay of 1s⁻¹e_delocalized into the 2p⁻² final states dominates again. The right panel schematically shows the dependence of the delocalized 2p⁻² (blue, vertical oval) and localized 2p⁻²3p (red, diagonal oval) final states on the incoming radiation energy.