Electronic Non-adiabatic Dynamics in Enhanced Ionization of Isotopologues of H$_2^+$ from the Exact Factorization Perspective

TL;DR

This paper investigates how nuclear mass affects enhanced ionization in isotopologues of H$_2^+$ using the exact factorization approach, revealing the importance of dynamical electron-nuclear correlation in the driving potential.

Contribution

It introduces a detailed analysis of nuclear-mass dependence in non-adiabatic electron dynamics using the exact factorization framework, including component decomposition and approximate models comparison.

Findings

Nuclear mass significantly influences the exact potential components.

Decomposition of the potential reveals distinct contributions from different wavefunction components.

Approximate models show varying accuracy in capturing the exact electron dynamics.

Abstract

It was recently shown that the exact potential driving the electron's dynamics in enhanced ionization of H$_2^+$ can have large contributions arising from dynamical electron-nuclear correlation, going beyond what any electrostatics-based model can provide[1]. This potential is defined via the exact factorization of the molecular wavefunction that allows the construction of a Schr\"odinger equation for the electronic system, in which the potential contains exactly the effect of coupling to the nuclear system and any external fields. Here we study enhanced ionization in isotopologues of H$_2^+$ in order to investigate nuclear-mass-dependence of these terms for this process. We decompose the exact potential into components that naturally arise from the conditional wavefunction, and also into components arising from the marginal electronic wavefunction, and compare the performance of propagation on these different components as well as approximate potentials based on the quasi-static or Hartree approximation with the exact propagation. A quasiclassical analysis is presented to help analyse the structure of different non-electrostatic components to the potential driving the ionizing electron.