Attosecond Water Radiolysis Dynamics: Modeling the X-ray Pump/X-ray Probe Experiment*

Ultrafast tunable X-ray pump/X-ray probe methodology allows us to dissect the entire radiolysis process from inception onwards. A tunable X-ray pump selects molecular orbitals being ionized and a tunable X-ray probe interrogates, on a site-specific basis, migration of holes and ensuing chemical reactions. This talk focuses on computational studies of the X-ray pump/X-ray probe experiment. We developed and applied the multireference configuration interaction approach to simulate the spectroscopic characteristics of transient inner valence holes in radiolysis of water. XAS near O K-edge spectra were computed using the tetrahedrally coordinated water pentamer model and compared to experiments. This work established experimental and quantum computational frameworks for attosecond radiolysis studies.