Application of the density functional theory derived orbital-free embedding potential to calculate the splitting energies of lanthanide cations in chloroelpasolite crystals

Abstract

Ligand field splitting energies of lanthanides Ln 3+ (Ln = from Ce to Yb) in octahedral environment are calculated using the Hohenberg-Kohn theorems based orbital-free embedding formalism. The lanthanide cation is described at orbital level whereas its environment is represented by means of an additional term in the Kohn-Sham-like one-electron equations expressed as an explicit functional of two electron densities: that of the cation and that of the ligands. The calculated splitting energies, which are in good agreement with the ones derived from experiment, are attributed to two main factors: (i) polarization of the electron density of the ligands, and; (ii) ion-ligand Pauli repulsion.

Electronic fine structure calculation of [Gd(DOTA)(H2O)]– using LF-DFT: The zero field splitting

“…But for further investigations this reduction to an atomic problem promisses an improvement, not least as it has already been mentioned in reference [15], that the splitting energies "[...] obtained from embedding calculations are clearly superior to that derived from supermolecular KohnSham results for the whole system". Newman and Ng give in reference [28] an explanation using Angular Overlap Theory.…”

“…It has been showed by Zbiri et al [15] that the qualitative behaviour of the Kohn-Sham Molecular-Orbitals with dominant Gd f -character and therefore corresponding to f -orbitals can be corrected using a so-called embedding potential. But as one can see out of table 1 this does not influence our result significantly.…”

Nonuniform Continuum Model for Solvatochromism Based on Frozen‐Density Embedding Theory

“…This manifests itself in a rather weak dependence of the numerical results on the choice for 1 B ðrÞ [25] and reflects the variational principle basis of FDET. The attribution of the change of the excitation energies, which result from the optimization of 1 B ðrÞ, only to the electronic polarization of the environment as previously reported (see a recent publication by Daday et al, [26] in which the FDET embedding potential was used to obtain excited states of a system described by means of embedded interacting wave function, or our own work on embedded trivalent cation in highly polarizable environment) [27] has only qualitative value. The effect due to the polarization of the electron density of the environment on the properties of the embedded species cannot be separated from the effect due to the error in the used approximation for the non-additive kinetic potential.…”

Electronic fine structure calculation of metal complexes with three-open-shell s, d, and p configurations

“…At the very beginning ligand field theory was operated with only empirical parameters [6,7]. However in the last few decades, the ligand field concept was often used in conjunction with first principles modeling studies either at the wavefunction [8][9][10] or density functional levels of theory [11][12][13][14][15]. The important growth of computational technics also has a non-negligible impact on the development of non-empirical ligand field calculation.…”