The surprising metastability of TeH2+

Area of Science:

• Theoretical Chemistry
• Computational Physics
• Quantum Chemistry

Background:

• Diatomic molecules and their electronic states are fundamental to understanding chemical bonding and reactivity.
• Investigating multiply charged molecular ions presents unique challenges due to strong inter-electron repulsion and complex potential energy surfaces.

Purpose of the Study:

• To perform a high-level ab initio investigation of the electronic states of the diatomic dication TeH(2+).
• To elucidate the metastability, electronic structure, and potential energy curves, including relativistic effects, of TeH(2+).
• To guide future experimental characterization of this novel species.

Main Methods:

• Ab initio electronic structure calculations.
• Construction of potential energy curves for both spin-orbit (Ω) and non-relativistic (Λ+S) states.
• Simulation of double ionization spectra.
• Mass spectrometric investigation.

Main Results:

• The study confirms the metastability of TeH(2+) and reveals a rich manifold of electronic states, contrasting with the simpler TeH molecule.
• Significant spin-orbit interactions were identified, particularly impacting energy barriers near state crossings.
• The binding is rationalized as a covalent bond, with dissociation into singly charged fragments explained by electron affinities.
• Simulated spectra and mass spectrometry corroborate the predicted transient existence.

Conclusions:

• TeH(2+) exhibits a complex electronic structure with significant relativistic effects, making it a promising candidate for spectroscopic study.
• The calculated electronic states and metastability provide a theoretical foundation for experimental verification.
• The findings contribute to the understanding of bonding in multiply charged diatomic systems.