Observation of Renner–Teller and predissociation coupled vibronic intensity borrowing in dissociative electron attachment to OCS

What is it about?

This article demonstrates how Born-dipole forbidden vibronic intensity borrowing occurs in the OCS molecule's dissociative electron attachment process. This study reveals the breakdown of both the dipole-Born and Born-Oppenheimer approximation.

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Photo by Emiliano Vittoriosi on Unsplash

Photo by Emiliano Vittoriosi on Unsplash

Why is it important?

In this study, we observed a few basic quantum mechanical effects, as listed below. 1. The Renner-Teller effect of molecular rotations and vibrations on the electronic spectra of linear molecules in degenerate electronic states (Pi, Delta, ..). 2. Non-radiative predissociation continuum violates the Born-Oppenheimer approximation through the Landau-Zener quantum tunnelling in avoided crossings. 3. Molecular symmetry breaking by low energy electron attachment process. 4. Observation of Dipole-forbidden Vibronic intensity borrowing event. 5. Axail recoil violation of triatomic molecular ion in a dissociative state. 6. Speed-dependent angular anisotropy of S- fragment. 7. Bimodal population in most probable kinetic energy distribution of the S- product. 8. First time, we observed core-excited resonace in a vibrationally excited state. 9. CAP-EOM-EA-CCSD-based electronic structure calculations probe the resonances of OCS and Renner-Teller splitting. Complex absorbing potential (CAP) based approaches are accurate and advantageous in probing electronic resonances.

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