Above-threshold ionization (ATI) in multicenter molecules: the role of the initial state

TL;DR

This paper extends an analytical model for above-threshold ionization in multicenter molecules, incorporating detailed molecular ground state information to better understand electron dynamics during strong laser interactions.

Contribution

It introduces a more accurate description of the molecular ground state using quantum chemistry data, enabling detailed analysis of ATI in complex multicenter molecules.

Findings

Inclusion of molecular symmetries and orbital nodes improves model accuracy.

Extension of the model to molecules with more than three centers is straightforward.

The approach maintains analytical simplicity while capturing essential physics.

Abstract

A possible route to extract electronic and nuclear dynamics from molecular targets with attosecond temporal and nanometer spatial resolution is to employ recolliding electrons as `probes'. The recollision process in molecules is, however, very challenging to treat using {\it ab initio} approaches. Even for the simplest diatomic systems, such as H$_2$, today's computational capabilities are not enough to give a complete description of the electron and nuclear dynamics initiated by a strong laser field. As a consequence, approximate qualitative descriptions are called to play an important role. In this contribution we extend the work presented in N. Su\'arez {\it et al.}, Phys.~Rev. A {\bf 95}, 033415 (2017), to three-center molecular targets. Additionally, we incorporate a more accurate description of the molecular ground state, employing information extracted from quantum chemistry software packages. This step forward allows us to include, in a detailed way, both the molecular symmetries and nodes present in the high-occupied molecular orbital. We are able to, on the one hand, keep our formulation as analytical as in the case of diatomics, and, on the other hand, to still give a complete description of the underlying physics behind the above-threshold ionization process. The application of our approach to complex multicenter - with more than 3 centers, targets appears to be straightforward.