Structure and stability of aquotetrafluorouranyl(VI) in the solid state — Density functional study of [UO₂F₄(H₂O)][NMe₄]₂·2H₂O^,

Abstract

IntroductionApproximate density functional theory (DFT) has fertilized computational transition-

Insights into Uranyl Chemistry from Molecular Dynamics Simulations

“…[20] In contrast, the water ligand is computed to be bound in the full periodic crystal of the known solid [UO 2 F 4 (H 2 O)](NMe 4 ) 2 ·2 H 2 O. [46] The bonding between U and water in this anion is thus strongly affected by the surrounding medium, and the counterions in particular. Because the simple background charge appeared to be insufficient in this case, explicit counterion effects in solution were subsequently evaluated with NH 4 + as model ions.…”

Effect of Counterions on the Structure and Stability of Aqueous Uranyl(VI) Complexes. A First-Principles Molecular Dynamics Study

“…This result appeared to be at odds with experiment, because this ion has been characterized by X-ray crystallography 4 and because there is evidence for its existence in aqueous solution from EXAFS data. 5 6 Because the EXAFS experiments have employed a large (9-fold) excess of NaF in order to produce the tetrafluoride, it has been speculated that this excess of counterions in solution, which was not included in the CPMD simulations, could help to stabilize the water ligand. 2f We now report the first CPMD simulations addressing this question by taking counterions explicitly into account.…”