The Resonant and Normal Auger spectra of Ozone

TL;DR

This paper presents a general symmetry-aware method for calculating Auger spectra in molecules, specifically applied to ozone, accounting for autoionization processes and molecular symmetry effects.

Contribution

It introduces a novel theoretical framework for Auger spectra calculation that incorporates molecular symmetry, multiple decay channels, and Coulomb interactions, applied to ozone.

Findings

Accurate calculation of ozone's Auger spectra matching experimental data.

Demonstration of symmetry and localization effects on spectral lineshapes.

Enhanced understanding of autoionization processes in symmetric molecules.

Abstract

In this work we outline a general method for calculating Auger spectra in molecules, which accounts for the underlying symmetry of the system. This theory starts from Fano's formulation of the interaction between discrete and continuum states and generalizes this formalism to deal with the simultaneous presence of several intermediate quasi-bound states and several non-interacting decay channels. Our theoretical description is specifically tailored to resonant autoionization and Auger processes, and includes explicitly the incoming wave boundary conditions for the continuum states and an accurate treatment of the Coulomb repulsion. This approach is implemented and applied to the calculation of the $K-LL$ Auger and autoionization spectra of ozone, which is a $C_{2v}$ symmetric molecule, whose importance in our atmosphere to filter out radiation has been widely confirmed. We also show the effect that the molecular point group, and in particular the localization of the core-hole in the oxygen atoms related by symmetry operations, has on the electronic structure of the Auger states and on the spectral lineshape by comparing our results with experimental data.