Oxygen K-edge X-ray Absorption Spectra

The aim of this thesis is to critically review and theoretically investigate oxygen K edge absorption spectra in oxide molecules and solids. The research making up the content of this thesis in Chapter 1, Chapter 2,Chapter 4 and Chapter 6 is the result of an extensive team work aiming to explore the available theoretical and experimental data on oxygen 1s XASspectra on molecular and solid systems. We discuss important aspects of various detection routes, highligth the differences and benefits of the availabletheoretical models and explore the applicability on the study of catalytic re- actions. Emphasizing both observational and theoretical aspects, this work provides a critical perspective on oxygen K edge absorption spectra. Chap- ter 3 and Chapter 5 aim at detailed investigations of two popular approachesto the modelling of K edges in molecular and solid systems: the coupled cluster hierarchy of methods and the DFT-based ∆SCF. The results of Chapter 3 and Chapter 5 test the performances of the computational methodology chosen for the simulation of K edges in formaldehyde and derivatives and alkaline earth metal oxides and contribute to a further understanding of the electronic structure of the investigated systems