Electrons as an environment for nuclei within molecules: a quantitative assessment of their contribution to a classical-like molecular structure

TL;DR

This paper investigates how electrons influence the classical-like structures of molecules by analyzing their role in nuclear localization and stability, revealing their partial contribution to molecular geometry and symmetry-breaking.

Contribution

It provides a quantitative assessment of electrons' role in nuclear localization and stability within molecules, highlighting their influence on molecular structure.

Findings

Electrons contribute to nuclear localization around specific geometries.

Electronic environment reduces off-diagonal RDM elements, aiding stability.

Electrons alone do not explain molecular symmetry-breaking.

Abstract

Molecular structure is often considered as emerging from the decoherence effect of the environment. Electrons are part of the environment of the nuclei in a molecule. In this work, their contribution to the classical-like geometrical relationships often observed between nuclei in molecular systems is investigated. Reduced density matrix (RDM) elements are evaluated from electron-nucleus wave functions. The computational results show that the electrons play a role in the localization of the nuclei around specific geometries. Although the electronic environment alone cannot explain molecular symmetry-broken isomers, it can contribute to their dynamical stability by reducing off-diagonal RDM elements.