Abstract
We report two-dimensional electron energy-loss spectra of . The high-resolution experiment reveals a counterintuitive fine structure at energy losses where states form a vibrational pseudocontinuum. Guided by the symmetry of the system, we constructed a four-dimensional nonlocal model for the vibronic dynamics involving two shape resonances (forming a Renner-Teller doublet at the equilibrium geometry) coupled to a virtual state. The model elucidates the extremely non-Born-Oppenheimer dynamics of the coupled nuclear motion and explains the origin of the observed structures. It is a prototype of the vibronic coupling of metastable states in continuum.
- Received 11 February 2022
- Revised 20 April 2022
- Accepted 20 May 2022
DOI:https://doi.org/10.1103/PhysRevLett.129.013401
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society