Ultrafast Relaxation Dynamics of Inner-Shell Vacancies in Hydrated Pyrrole

TL;DR

This study uses advanced real-time quantum simulations to explore ultrafast relaxation processes in hydrated pyrrole, revealing how initial vacancies influence decay pathways and charge transfer mechanisms.

Contribution

It introduces a real-time TDDFT approach combined with Ehrenfest dynamics to analyze vacancy-dependent relaxation in hydrated pyrrole.

Findings

Decay dynamics depend on initial vacancy location.

Intermolecular Coulombic decay and electron transfer are prominent.

Different decay channels are activated depending on the ionized site.

Abstract

We employ real-space, real-time time-dependent density functional theory (TDDFT) combined with Ehrenfest dynamics to investigate ultrafast intermolecular relaxation following inner-valence ionization in hydrated pyrrole. This time-dependent approach treats electronic and nuclear motions simultaneously, allowing the description of electronic excitation, charge transfer, ionization, and nuclear motion.When the initial vacancy in the O 2s 1 state is created on the water molecule, the system predominantly undergoes intermolecular Coulombic decay (ICD) and electron-transfer mediated decay (ETMD), accompanied by pronounced charge transfer between pyrrole and water. In contrast, ionization of the pyrrole site for N 2s electron leads to both ICD and Auger decay channels. These results demonstrate that the decay dynamics are strongly governed by the initial vacancy location, offering microscopic insight into intermolecular energy-transfer mechanisms in hydrated molecular systems.