Quasirelativistic energy-consistent 5f-in-core pseudopotentials for trivalent actinide elements

Abstract

Quasirelativistic energy-consistent 5f-in-core pseudopotentials modelling trivalent actinides, corresponding to a near-integral 5f n occupation (n = 0-14 for Ac-Lr), have been generated. Energy-optimized (6s5p4d), (7s6p5d), and (8s7p6d) primitive valence basis sets contracted to polarized double to quadruple zeta quality as well as 2f1g correlation functions have been derived. Corresponding smaller basis sets (4s4p3d), (5s5p4d), and (6s6p5d) suitable for calculations on actinide(III) ions in crystalline solids form subsets of these basis sets designed for calculations on neutral molecules. Results of Hartree-Fock test calculations for actinide(III) monohydrates and actinide trifluorides show a satisfactory agreement with corresponding calculations using 5f-in-valence pseudopotentials. Even in the beginning of the actinide series, where the 5f shell is relatively diffuse, only quite acceptable small deviations occur as long as the 5f-shell does not participate significantly in covalent bonding.

Electronic structure of crystalline uranium nitride: LCAO DFT calculations

“…The 5f-in-core RECP81SKs were presented for trivalent actinide elements in [26] and tested for actinide (III) molecular compounds. Table 7 Comparison of the results for pseudopotentials "5f-in-valence" and "5f-in-core" (DFT PW91 LCAO calculations).…”

Efficient quantum chemical valence-only treatments of lanthanide and actinide systems

“…As illustration we show An-O bond distances and An 3+ -H 2 O binding energies for actinide monohydrate ions in Fig. 6 [49]. It is obvious that the 5f-in-core LPP approach is able to reproduce trends obtained with the more rigorous 5f-in-valence SPP approach as well as with AE DHF/DC calculations [69].…”

“…Although the 5f shell of the actinides is radially more extended than the 4f shell of the lanthanides and for the lighter actinides also actively participates in chemical bonding, it proved to be possible to derive 5f-in-core PPs for actinides with valencies ranging from two to six [49,50,51]. Their applications saves a significant amount of computer ressources with respect to an explicit treatment of the 5f shell, especially with respect to AE calculations.…”

“…FIGURE 6. Actinide-oxygen distances (Å) and An 3+ -H 2 O binding energies (eV) from 4f-in-core (large-core, LPP) and 4f-invalence (small-core, SPP) pseudopotential restricted Hartree-Fock (RHF) calculations [49] in comparison to all-electron DiracHartree-Fock (AE DHF) results [69]. The arrows denote estimates of a correction of the basis set superposition error in the AE results taken from the corresponding lanthanide systems.…”

A New 5,5′‐Bitetrazole Thorium(IV) Compound: Synthesis, Crystal Structure and Quantum Chemical Investigation

“…Generally, the atomic Th IV subunits of rare gas-like [Rn]7s 0 5f 0 6d 0 configurations have been modeled within the relativistic large-core pseudopotential (PP) approximation: [21] In a somewhat simplified picture, Th IV atomic orbitals with main quantum numbers n Յ 5 are replaced by potential functions fitted to accurate scalar-relativistic Wood-Boring all-electron reference data; the validity of this approach has recently been established. [22] For Th IV a PP-compatible (5s6p4d2f1g)/[4s4p3d2f1g] Gaussian basis set with additional diffuse two s, one p, and one d functions [21] has been used. For H, C, and O the standard TZVP basis sets of Schäfer et al [23] have been applied.…”