Search for long lasting electronic coherence using on-the-fly ab initio semiclassical dynamics

TL;DR

This study combines high-level ab initio methods with semiclassical dynamics to identify small molecules with long-lasting electronic coherences, revealing candidates with up to 10 fs coherence duration and advancing understanding of electron-nuclear interactions.

Contribution

It introduces a comprehensive on-the-fly simulation approach to find molecules with prolonged electronic coherence, including full-dimensional coupled electron-nuclear dynamics.

Findings

Most molecules do not sustain long electronic coherences after ionization.

Several molecules exhibit up to 10 fs of electronic coherence.

Full-dimensional simulations reveal nuclear effects on coherence duration.

Abstract

Using a combination of high-level ab initio electronic structure methods with efficient on-the-fly semiclassical evaluation of nuclear dynamics, we performed a massive scan of small polyatomic molecules searching for a long lasting oscillatory dynamics of the electron density triggered by the outer-valence ionization. We observed that in most of the studied molecules, the sudden removal of an electron from the system either does not lead to the appearance of the electronic coherence, or the created coherences become damped by the nuclear rearrangement on a time scale of a few femtoseconds. However, we report several so far unexplored molecules with the electronic coherences lasting up to 10 fs which can be good candidates for experimental studies. In addition, we present the full-dimensional simulations of the electronic coherences coupled to nuclear motion in several molecules which were studied previously only in the fixed nuclei approximation.