MODELING OF THE HYDRATION SPHERE OF GADOLINIUM(III) ION USING DENSITY-FUNCTIONAL THEORY

The hydrated gadolinium(III) ion cluster Gd3+(H2O)(x), with x=8,9, was studied using density functional theory. The different conformations of the first hydration shell were calculated. For x=8, the results for the cubic conformation correspond to previously published Hartree-Foc k and MP2 results, whereas much lower energies were found for the squa re antiprismatic and dodecahedral conformations. For x=9, the energy o f the tricapped trigonal prism is nearly identical to the one of the a ntiprism plus and extra free water molecule.