Combining theoretical chemistry and XANES multi-edge experiments to probe actinide valence states

Polarization Dependent High Energy Resolution X-ray Absorption Study of Dicesium Uranyl Tetrachloride

“…Such variations are demonstrated for 90°a nd 0°geometries in quantum chemical calculations of U M 5 -edge PD-XANES of UO 2 (NO 3 ) 2 ·6H 2 O. 24 3.2. ZORA ADF Calculations.…”

Exploring Actinide Materials Through Synchrotron Radiation Techniques

“…It has been reported that the FEFF code can provide successful interpretation of actinide XAFS spectroscopy . All the XAFS codes need initial models including atomic positions and electronic structures of the studied compounds . These input parameters can be acquired through other experimental techniques or computational chemistry including quantum chemical and molecular mechanics calculations.…”

Uranium speciation in weathered granitic waste rock piles: an XAFS investigation

“…Because of its sensitivity to low concentrations of the target element even in amorphous or crystalline form and to the parameters that determine the chemical speciationvalence and local geometry and the types of neighbor atoms and their distances from the absorber -EXAFS is acknowledged as one of the most incisive methods for obtaining such information. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Here we apply it to study the U speciation in granitic rocks, arena and technosoils, related to the weathering of the waste rock piles, performing U L 3 XAFS measurements on two categories of samples containing various concentration of U in phyllosilicates or uranyl phosphates paragenese. Reference samples of U bound to clay minerals (montmorillonite, kaolinite and illite) were prepared in the laboratory, and natural samples of autunite and soddyite were also measured.…”