Correlated dynamics of the motion of proton-hole wave-packets in a photoionized water cluster

TL;DR

This study investigates the ultrafast correlated motion of electrons and protons in a photoionized water cluster, revealing a decay mechanism driven by electrostatic repulsion and strong nuclear-electronic coupling.

Contribution

It introduces a quantum-dynamical approach to describe coupled electron-proton dynamics and highlights the importance of non-adiabatic effects in ionized hydrogen-bonded systems.

Findings

Proton-hole dynamics are driven by electrostatic repulsion.

Non-adiabatic effects are crucial for electron-proton localization.

Similar decay mechanisms may occur in other hydrogen-bonded systems.

Abstract

We explore the correlated dynamics of an electron-hole and a proton after ionization of a protonated water cluster by extreme ultra-violet (XUV) light. An ultrafast decay mechanism is found in which the proton--hole dynamics after the ionization are driven by electrostatic repulsion and involve a strong coupling between the nuclear and electronic degrees of freedom. We describe the system by a quantum-dynamical approach and show that non-adiabatic effects are a key element of the mechanism by which electron and proton repel each other and become localized at opposite sides of the cluster. Based on the generality of the decay mechanism, similar effects may be expected for other ionized systems featuring hydrogen bonds.