Hydration of Y ion; A Car-Parrinello molecular dynamics study

Ikeda, Takashi; Hirata, Masaru ; Kimura, Takaumi 

The solvation shell structure of Y and the dynamics of the hydrated ion in an aqueous solution of 0.8 YCl are studied in two conditions with and without an excess proton by using first principles molecular dynamics method. We find that the first solvation shell around Y contains eight water molecules forming a square antiprism as expected from X-ray absorption near edge structure in both the conditions we examined. A detailed analysis relying upon localized orbitals reveals that the complexation of water molecules with yttrium cation leads to a substantial amount of charge redistribution particularly on the oxygen atoms, giving rise to the chemical shifts of -20 ppm in O NMR relative to the computed nuclear shieldings of the bulk water.