A practical computational tool for actinide coordination chemistry (LFDFT): study of M4,5-edge core-to-core and valence-band resonant inelastic x-ray scattering

A great deal of spectroscopic methods have been developed to study actinide coordination chemistry, for example, high-energy resolution x-ray absorption/emission spectroscopy, core-to-core and valenceband resonant inelastic x-ray scattering (RIXS). RIXS techniques have been very powerful in deciphering electronic structure effects and helped advancing our understanding of the overall 5f electrons and their ability to participate in a chemical bond. However, investigating actinide M4,5-edge RIXS can be made possible hand in hand with theoretical models. In the last decades, we developed a DFT-based theory for coordination chemistry, the Ligand-Field Density-Functional Theory (LFDFT) model. This presentation reports recent developments in LFDFT, including extended method for modeling actinide M4,5-edge core-to-core and valence-band RIXS as well as the treatment of ligand-to-metal charge transfer for simulating covalent binding interactions. We will demonstrate that LFDFT can be used to calculate RIXS maps and to model RIXS spectral profiles from first principles. In a series of applications that are used to benchmark the theoretical model, including uranyl(VI) systems, actinide oxides, aqua Pu(III,IV,V,VI) complexes, Am(III) organometallics, etc., we will show that very good agreements with the experimental data can been reached. ... mehrFurthermore, LFDFT is also proposed to assess the bond covalency of the actinide-ligand interaction.