2018 eSSENCE meeting on “Multiscale modelling of materials and molecules

You are most welcome to register for the 2018 eSSENCE meeting at the Ångström Laboratory, Uppsala University, 11-13 June (lunch-to-lunch), https://sites.google.com/site/emultiscale2018/.

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.


Read more…