Vibronic Coupling through the Continuum in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>e</mml:mi><mml:mo>+</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>CO</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:math> System
J. Dvořák, Miloš Ranković, Karel Houfek, Pamir Nag, Roman Čurı́k, Juraj Fedor, M. Čı́žek
Abstract
We report two-dimensional electron energy-loss spectra of CO_{2}. The high-resolution experiment reveals a counterintuitive fine structure at energy losses where CO_{2} 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 Π_{u} doublet at the equilibrium geometry) coupled to a virtual Σ_{g}^{+} 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.