Femtosecond Core-Level Charge Transfer

We predict that ultrafast, few-femtosecond (fs) core-level charge transfer may occur following X-ray excitation, driven by nonadiabatic dynamics. Using the example of ethylene excited to its 1sπ* manifold, we predict that a transfer of core-electron density from one side of the molecule to the other occurs within 5 fs following broadband X-ray excitation, resulting in core-hole localization. These dynamics are predicted to occur within the Auger decay window, thus, in principle, rendering them observable.