Quantum Chemical Calculation for the Nuclear Safety Research: Complementary Tool to Spectroscopy and Electrochemistry

Quantum chemical calculations is capable of predicting various physicochemical properties of ions and molecules and may assist to further explore experimental chemistry. Among several different available theories, density functional theory (DFT) is a reasonable compromise between accuracy and computational time, and is nowadays widely used for the studies in physics, chemistry, and material science.
I will present several examples how DFT calculations can be used to better understand experimental actinide chemistry. The first example shows the calculations of luminescence properties of uranium(VI). The quenching of uranium(VI) luminescence in the presence of some types of organic and inorganic compounds are well reproduced by the DFT calculations and the quenching mechanism has been postulated. In another example, redox potentials of the actinide couple An(VI)/An(V) was studied for An = U, Np, Pu, Am. The unsolved question "What is the highest oxidation state of plutonium?" was discussed from theoretical viewpoint. The structures of various actinide complexes were also studied and they were disucussed together with EXAFS spectroscopy measurements at the Rossendorf Beamline in ESRF, France.