Research at the European XFEL: Small quantum systems research on water dimer dynamics

Olle Björneholm from the Uppsala University in Sweden explains how he probes ultrafast hydrogen bond dynamics in water with the X-ray laser of the European XFEL.
Water is the key solvent and natural environment for all species of biological interest. Its unique properties are intimately connected to the still incompletely understood intermolecular hydrogen bond. The investigation of the water dimer, as the smallest unit containing a hydrogen bond, is the first step toward the comprehension of the dynamics of liquid water upon exposure to X-ray beams.
Björneholm and his team will use X-ray-pump and -probe and Coulomb Explosion Imaging at the Small Quantum Systems instrument (SQS) to monitor and image the X-ray-induced water dimer dynamics in real time and space, including the few-femtosecond-timescale, non-local electronic decay and proton-transfer pathways. The experimental results combined with theoretical simulations will improve our understanding of water.