The complexation of uranium and neptunium with a variety of ligands such as carbonate and carboxylate expected to be present under environmental conditions was studied computationally by a relativistic density functional method. The agreement of theoretical and experimental data was significantly improved if short-range solvent effects are considered in addition to modeling of long-range interactions. The computational results explain the stability of the triuranyl hexa(carbonato) complex and confirm the suggested distribution of isomers of uranyl hemicarbonate complexes in aqueous solution. The analysis of geometric parameters of actinyl monocarboxylate complexes suggests a new interpretation of EXAFS derived data as the average equatorial actinyl oxygen distance is found to be independent of the carboxylate coordination mode. Thus, the classification of the actinyl humate coordination as monodentate on the basis of this parameter is questionable and requires further investigations.    «

The complexation of uranium and neptunium with a variety of ligands such as carbonate and carboxylate expected to be present under environmental conditions was studied computationally by a relativistic density functional method. The agreement of theoretical and experimental data was significantly improved if short-range solvent effects are considered in addition to modeling of long-range interactions. The computational results explain the stability of the triuranyl hexa(carbonato) complex and co...    »