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Solvent effects on uranium(VI) fluoride and hydroxide complexes studied by EXAFS and quantum chemistry.
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TLDR
Solvent effects were shown to give the main contribution to the observed structure variations between the uranium(VI) tetrahydroxide and the tetrafluoride complexes.Abstract:
The structures of the complexes UO2Fn(H2O)5-n2-n, n = 3−5, have been studied by EXAFS. All have pentagonal bipyramid geometry with U−F of and U−H2O distances equal to 2.26 and 2.48 A, respectively. On the other hand the complex UO2(OH)42- has a square bipyramid geometry both in the solid state and in solution. The structures of hydroxide and fluoride complexes have also been investigated with wave function based and DFT methods in order to explore the possible reasons for the observed structural differences. These studies include models that describe the solvent by using a discrete second coordination sphere, a model with a spherical, or shape-adapted cavity in a conductor-like polarizable continuum medium (CPCM), or a combination of the two. Solvent effects were shown to give the main contribution to the observed structure variations between the uranium(VI) tetrahydroxide and the tetrafluoride complexes. Without a solvent model both UO2(OH)4(H2O)2- and UO2F4(H2O)2- have the same square bipyramid geometry...read more
Citations
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Segmented contraction scheme for small-core lanthanide pseudopotential basis sets
TL;DR: In this paper, a Gaussian (14s13p10d8f6g)/[10s8p5d4f3g] valence basis set using a segmented contraction scheme was derived for relativistic energyconsistent small core lanthanide pseudopotentials of the Stuttgart-Bonn variety.
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Solution and solid-state structural chemistry of actinide hydrates and their hydrolysis and condensation products.
Karah E. Knope,Lynda Soderholm +1 more
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Oxo ligand functionalization in the uranyl ion (UO22
Skye Fortier,Trevor W. Hayton +1 more
TL;DR: A review of the chemistry of the two oxo ligands of the uranyl ion can be found in this article, where the authors explore the interaction of uranyl oxoxide ligands with Lewis acids, and outline attempts to selectively functionalize the oxo-ligands by chemical means.
Journal ArticleDOI
Solution coordination chemistry of actinides: Thermodynamics, structure and reaction mechanisms
TL;DR: A review on the combination of experimental and theoretical methods to obtain microscopic information on the chemistry of actinides in aqueous solution can be found in this article, where a comparison of experimental data with those obtained using quantum chemical methods is provided.
Journal ArticleDOI
The Coordination of Uranyl in Water: A Combined Quantum Chemical and Molecular Simulation Study
TL;DR: The results show a uranyl ion with five water molecules coordinated in the equatorial plane, the first fully ab initio determination of the solvation of the uranyl ions in water.
References
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Density‐functional thermochemistry. III. The role of exact exchange
TL;DR: In this article, a semi-empirical exchange correlation functional with local spin density, gradient, and exact exchange terms was proposed. But this functional performed significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
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Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density
TL;DR: Numerical calculations on a number of atoms, positive ions, and molecules, of both open- and closed-shell type, show that density-functional formulas for the correlation energy and correlation potential give correlation energies within a few percent.
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Quantum Calculation of Molecular Energies and Energy Gradients in Solution by a Conductor Solvent Model
Vincenzo Barone,Maurizio Cossi +1 more
TL;DR: In this paper, a new implementation of the conductor-like screening solvation model (COSMO) in the GAUSSIAN94 package is presented, which allows Hartree−Fock (HF), density functional (DF) and post-HF energy, and HF and DF gradient calculations: the cavities are modeled on the molecular shape, using recently optimized parameters, and both electrostatic and nonelectrostatic contributions to energies and gradients are considered.
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Multiple-scattering calculations of x-ray-absorption spectra
TL;DR: A high-order multiple-scattering approach to the calculation of polarized x-ray-absorption spectra, which includes both x- Ray- absorption fine structure and x-Ray- absorption near-edge structure, is presented.
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Ab initio energy-adjusted pseudopotentials for elements of groups 13-17
TL;DR: In this article, quasi-relativistic energy-adjusted pseudopotentials for the elements of groups 13-17 up to atomic number 53 (I) are presented together with corresponding energy-optimized valence basis sets.