Electronic Structure and Chemical Bonding of [AmO₂(H₂O) ]^2+/1

Systematic americyl-hydration cations were investigated theoretically to understand the electronic structures and bonding in [(AmO₂)(H₂O) ]^2+/1+ (n = 1-6). We obtained the binding energy using density functional theory methods with scalar relativistic and spin-orbit coupling effects. The geometric structures of these species have been investigated in aqueous solution via an implicit solvation model. Computational results reveal that the complexes of five equatorial water molecules coordinated to americyl ions are the most stable due to the enhanced ionic interactions between the AmO₂ ^2+/1+ cation and multiple oxygen atoms as electron donors. As expected, Am-O_water bonds in such series are electrostatic in nature and contain a generally decreasing covalent character when hydration number increases.