Ab initio Hartree Fock study of structure of hydrated uranyl and neptunyl ions

Abstract

  Ab initio Hartree Fock calculations of hydrated uranyl and neptunyl ions have been carried out inclusive of the primary and the secondary hydration spheres. The results suggest that the hydration number n = 5 being the most stable for species UO₂²⁺, NpO₂⁺, and NpO₂²⁺. The result for NpO₂⁺ is in conflict with the previous Hartree Fock calculation which only included the primary hydration sphere, It was concluded that the hydration study of the actinyls should be implemented inclusive of not only the primary but also the secondary hydration sphere. It was also found out that the apical waters bonding to the axial oxygen of the actinyls play an important role in the electronic structure of the hydrated actinyls.