Do the ``Ligand Field'' Parameters in Lanthanides Represent Weak Covalent Bonding?

Abstract

High order crystal field invariants and the determination of lanthanide crystal field parameters J. Chem. Phys. 84, 4470 (1986); 10.1063/1.450018Comparison of calculated and experimental 4f→4f intensity parameters for lanthanide complexes with isotropic ligands

Insulator to semiconductor transition and magnetic properties of the one-dimensionalS=12systemIn2Möller1, Taetz2, Hollmann3 et al. 2007Phys. Rev. B135100View full textAdd to dashboardCite

“…20,21,22 . The AOM calculations include the interatomic distances and angles derived from the single crystal structure determination, and therefore, distortions from an octahedral ligand field can be accounted for.…”

Occupation matrix control of d- and f-electron localisations using DFT + U

“…59 This is in part due to the f-shell being more contracted than the d-shell, causing the magnitude of the f orbital splitting to be less pronounced. 60 In addition, there is no universal set of f orbitals which is applicable to all materials. 61 The general set, determined in the normal manner by the product of the angular factors of the orbital, for example, does not contain any sets of orbitals which are triply degenerate, as predicted by group theory for materials in a cubic field.…”

Rationalization of Spectra of Rare Earths in Condensed Matter

“…The Slater-Condon-Shortley parameters are the same (within 3 percent) in Ln(IIΙ) and Ln+3 . Technically, the demise of the model [13] of the minute non-spherical part of the Madelung potential as source of weak energy differences in Ln(ΙIΙ) and Ln(IΙ) compounds has been remedied [48,49] by the same angular overlap model as dq, but the antibonding effects 50 times smaller, and not decided mainly by the kind of ligand Χ, but rather by a strong decrease for longer Ln-X distances. It may be added that transthorium elements M(III) are quite similar to J-levels of Ln(ΙIΙ), but higher oxidation states U(IV), U(V), Νp(IV), Np(V), Νp(VI), Pu(IV)... have stronger antibonding effects on 5f q than M(III), but again determined by shorter M-Χ distances, e.g.…”