Molecular Physics seminar

Modeling core-level spectroscopy of surfaces processes

by Henrik Öberg (Molecular Physics Division)

FA 31 ()

FA 31

Core-level spectroscopies offer means to study surface phenomena on an electronic structure level. Chemical bonds and even reactions can be studied and understood in detail using these experimental techniques but often complementary simulations are required in order to make correct interpretations of the experimental results. In this talk an introduction to how we simulate x-ray absorption (XAS) and emission (XES) spectroscopy within a density functional theory framework will be given, followed by a demonstration of the applicability of the methods in terms of a few examples; the bonding mechanism of CO adsorbed on Fe(100) will be discussed as will the laser-induced CO desorption on Ru(0001) in which a weakly bound precursor state to desorption/adsorption is identified. A limitation to the XES approach, which neglects vibrational interference effects, will also be demonstrated in the application to O/Pt(111) and O/Pt/Cu(111) and how including these effects yield near-quantitative agreement with experiment for the same systems.