First-principles study of the separation of Am(III)/Cm(III) from Eu(III) with Cyanex301.

The experimentally observed extraction complexes of trivalent lanthanide Eu(III) and actinide Am(III)/Cm(III) cations with purified Cyanex301 [bis(2,4,4-trimethylpentyl)dithiophosphinic acid, HBTMPDTP denoted as HL], i.e., ML(3) (M = Eu, Am, Cm) as well as the postulated complexes HAmL(4) and HEuL(4)(H(2)O) have been studied by using energy-consistent 4f- and 5f-in-core pseudopotentials for trivalent f elements, combined with density functional theory and second-order Møller-Plesset perturbation theory.

Computational study of lanthanide(III) hydration.

Lanthanide(iii) hydration was studied by utilizing density-functional theory and second-order Møller-Plesset perturbation theory combined with scalar-relativistic 4f-in-core pseudopotentials and valence-only basis sets for the Ln(iii) ions. For [Ln(iii)(H(2)O)(h)](3+) (h = 7, 8, 9) and [Ln(iii)(H(2)O)(h-1)·H(2)O](3+) (h = 8, 9) molecular structures, binding energies, entropies and energies of hydration as well as Gibbs free energies of hydration were calculated using (8s7p6d3f2g)/[6s5p5d3f2g] basis sets for Ln(iii) and aug-cc-pV(D,T)Z basis sets for O and H in combination with the COSMO solvation model. At the generalized gradient approximation level of density-functional theory a preferred hydration number of 8 is found for La(iii)-Tm(iii) and 7 for Yb(iii)-Lu(iii), whereas hybrid density-functional theory predicts a hydration number 8 for all Ln(iii).