Fig. 3: Impact of the electron density and nuclear dynamics on the chemical shift.
From: Observation of site-selective chemical bond changes via ultrafast chemical shifts
Calculated time-resolved C1s XPS spectra of the (a) core-excited state, (b) dissociative Φ Auger state, and (c) bound Π1 Auger state, for different time delays. The spectra are displayed at the average position of the nuclear wavepacket at the respective time. The spectra are color coded by the time delay displayed in panel (c). Panels d–f show the corresponding potential energy curves together with the nuclear wavepacket at different time delays. The difference in Mulliken charges ΔQm at the C (solid line) and O (dashed line) sites, between the corresponding state and the ground state are shown in panels g–i. The average position of the nuclear wavepacket at different time delays is indicated as vertical bars. The electron density difference (Δρ) between the excited states and the ground state is given in the insets, where blue and orange densities correspond to gain and loss with respect to the ground state, respectively. The core vacancy at the O site is highlighted by the dashed circle.
