The annual “Swedish eScience Academy” will take place in Uppsala October 16-17 (lunch-lunch).

Registration and more information on the event’s web page.

eSSENCE research in focus

First-principles modelling of the L-edge X-Ray Absorption Spectroscopy of Transition Metal Oxides and Organic Molecules with Transition Metals Centers

The x-ray absorption spectroscopy at the L-edge represents a unique tool to investigate the properties of highly correlated materials like transition metal (TM) oxides and organic compounds with TM centers. The underlying physical process is the photo-excitation of 2p electrons into unoccupied 3d levels. The latter are responsible for a variety of phenomena like spin ordering, Kondo resonances and superconductivity, of the uttermost relevance for possible applications. Moreover, when the L-edge absorption spectra are measured with circularly polarized x-rays, specific sum rules applied to the spectra provide a unique probe of the magnetic properties of ferromagnetic materials. The theoretical description of these electronic excitations still poses a big challenge for ab initio methods, and therefore novel computational approaches have to be developed. In fact, in addition to the intrinsic difficulty in describing the strong correlation of the d electrons, complex phenomena have necessarily to be accounted for, like the ligand field generated by the neighbouring atoms, the multiplet structure associated with the spin-orbit coupling in 2p and 3d shells as well as the final state with a 2p hole, all having a strong effect on the absorption spectra.


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