ArH2+ and NeH2+ as Global Minima in the Ar+/Ne+ + H2 Reactions: Energetic, Spectroscopic, and Structural Data

Abstract

In light of the recent discovery of ArH+ in the Crab nebula, it is shown through high-level quantum chemical comptuations that the global minima on the Ar+/Ne+ + H2 potential energy surfaces are ArH2+ and NeH2+. Hence, ArH2+ may be a necessary intermediate in the Ar+ + H2 -> ArH+ + H formation reaction proposed in the same work where ArH+ is first reported in the Crab nebula. ArH2+ is also probably an intermediate in the alternative Ar + H+2 -> ArH+ + H reaction. Additionally, it is shown that Ne+ + H2 -> NeH+2 will subsequently most likely yield Ne + H+2 and not NeH+ + H offering a possible rationale as to the absence of NeH+ in spectra obtained from the interstellar medium (ISM). Following from this, spectroscopic data (both rotational and vibrational) are provided for NeH2+ and ArH2+ through the use of highly-accurate quantum chemical quartic and cubic force fields. All possible isotopologues are also included for 20Ne, 22Ne, 36Ar, 38Ar, 40Ar, 1H, and D. The dipole moments for these systems are quite large at 5.61 D for NeH2+ and 4.37 D for ArH2+. The spectroscopic constants provided will aid in the potential detection of these open-shell noble gas dihydride cations in the ISM.

arXiv comment12 Pages, 4 Figures, 8 Tables, accepted for publication in MNRAS

References in corpus (7)

• Detection of a Noble Gas Molecular Ion, {36}ArH^+, in the Crab Nebula
• The Collisional Evolution of Debris Disks
• Ubiquitous argonium (ArH${}^{+}$) in the diffuse interstellar medium -- a molecular tracer of almost purely atomic gas
• Spectroscopic Constants and Vibrational Frequencies for l-C3H+ and Isotopologues from Highly-Accurate Quartic Force Fields: The Detection of l-C3H+ in the Horsehead Nebula PDR Questioned
• Photodissociation of interstellar ArH+
• New accurate measurement of 36ArH+ and 38ArH+ ro-vibrational transitions by high resolution IR absorption spectroscopy
• Comparative study of Rare Gas-H${}_2$ triatomic complexes

Cited by in corpus (5)

• The Interstellar Formation and Spectra of the Noble Gas, Proton-Bound HeHHe+, HeHNe+, & HeHAr+ Complexes
• A Closer Look at Some Gas-Phase Depletions in the ISM: Trends for O, Ge, and Kr vs. $F_{\ast }$, $f({\mathrm{H}}_2)$, and Starlight Intensity
• Extending the view of ArH+ chemistry in diffuse clouds
• Exploring the Possibility of Identifying Hydride and Hydroxyl Cations of Noble Gas Species in the Crab Nebula Filament
• Fate and detectability of rare gas hydride ions in nova ejecta: A case study with nova templates