Topological Studies related to Molecular Systems formed soon after the Big Bang: HeH2+ as the Precursor for HeH+

TL;DR

This paper explores the potential role of NACTs as a friction-like force in the formation of interstellar molecules, proposing HeH2+ as a precursor to HeH+ in the early universe, supported by topological and quantum chemical analysis.

Contribution

It introduces a novel hypothesis that NACTs can act as a dissipative force facilitating the formation of HeH2+ in space, linking topological quantum chemistry with astrophysical molecule formation.

Findings

NACTs exhibit singularities in triatomic systems.

HeH2+ could have formed via NACT-mediated processes.

HeH2+ detection in space is plausible in the future.

Abstract

In the early universe, following the nucleosynthesis, conditions were right for recombination processes to take place yielding neutral atoms H, He and Li. The understanding so far in astrophysics is that the first molecule to be formed was HeH+ by radiative association (He + H+ -> HeH+ + h(nu) and He+ + H -> HeH+ + h(nu). The recent report by Guesten et al (Nature, 568, 357, 2019) of detection of HeH+ in planetary Nebula NGC 7027 confirms its presence, but it does not conclusively prove the origin of this species. To create molecules from free moving quasi-ions surrounded by an electronic cloud, the Born-Oppenheimer-Huang (BOH) theory furnishes two kinds of forces, namely, one that results from the Potential Energy Surfaces (PESs) and the other from Non-Adiabatic Coupling Terms (NACTs). Whereas the PESs are known to manage slow moving quasi-ions the NACTs, with their, frequently, infinitely large values at the vicinity of the singularities can control the fast moving quasi-ions. To achieve that the BOH equation indicates that the NACTs are affecting the fast moving quasi-ions directly and if they are attributed with dissipative features or in other words to behave as a Friction Force they indeed could serve (like any other ordinary friction) as moderators for the fast atomic(ionic) species. It is proposed in the present paper that the triatomic HeH2+ was the precursor to HeH+ and it could have been formed by the (He, H, H)+ nuclei coming together under the electron cloud, facilitated by the NACTs between different electronic states acting as an astronomical friction force. This is possible because of the singularities in the NACTs for triatomic systems and NOT for diatomic systems. Although the existence of HeH2+ was established in the laboratory in 1996, it has not been detected in the interstellar media so far. But, there is no reason why it cannot be detected in near future.