The angular overlap model, an attempt to revive the ligand field approaches

Schäffer, Claus Erik; Jørgensen, Chr. Klixbüll

doi:10.1080/00268976500100551

Cited by 433 publications

(109 citation statements)

References 6 publications

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“…12,14,15 However, we can also consider other ways to parameterize the ligand field potential, since the Wybourne scheme is not very transparent from the chemical point of view. Another way to illustrate the ligand field potential is obtained using the concept of AOM following the work of Schäffer and Jørgensen 45 and Urland 46 for single-open-shell d and f electrons, respectively. In the case of the CaF 2 :Pr 3+ system for instance, we obtain the AOM parameters (in cm À1 ) e s (f) = 562, e p (f) = 202, e s (d) = 13 426 and e p (f) = 3644, knowing that the O h symmetry of the structure allows considering eight identical and equivalent fluoride ligands by symmetry (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The labels (f), (d) and (fd) next to the parameters emphasize the origin of the parameters to be a perturbation of the 4f, the 5d and both 4f, 5d orbitals of the lanthanide ion, respectively. The ligand field interaction can also be described with respect to the Angular Overlap Model (AOM), 45,46 requiring in the present case twoopen-shell f and d.…”

Section: Ligand Field Parametersmentioning

confidence: 99%

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Ligand field density functional theory for the prediction of future domestic lighting

Ramanantoanina

Urland

García‐Fuente

et al. 2014

Phys. Chem. Chem. Phys.

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We deal with the computational determination of the electronic structure and properties of lanthanide ions in complexes and extended structures having open-shell f and d configurations. Particularly, we present conceptual and methodological issues based on Density Functional Theory (DFT) enabling the reliable calculation and description of the f -d transitions in lanthanide doped phosphors. We consider here the optical properties of the Pr 3+ ion embedded into various solid state fluoride host lattices, for the prospection and understanding of the so-called quantum cutting process, being important in the further quest of warm-white light source in light emitting diodes (LED). We use the conceptual formulation of the revisited ligand field (LF) theory, fully compatibilized with the quantum chemistry tools: LFDFT. We present methodological advances for the calculations of the Slater-Condon parameters, the ligand field interaction and the spin-orbit coupling constants, important in the non-empirical parameterization of the effective Hamiltonian adjusted from the ligand field theory. The model shows simple procedure using less sophisticated computational tools, which is intended to contribute to the design of modern phosphors and to help to complement the understanding of the 4f n -4f nÀ1 5d 1 transitions in any lanthanide system.

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Section: Resultsmentioning

confidence: 99%

Section: Ligand Field Parametersmentioning

confidence: 99%

Ligand field density functional theory for the prediction of future domestic lighting

Ramanantoanina

Urland

García‐Fuente

et al. 2014

Phys. Chem. Chem. Phys.

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“…This formulation of the ligand field potential (eqn (6)) and related representation are like the Stevens parameters A k,q , 35,36 while elegant might be sometimes cumbersome and does not offer any chemical insight. To circumvent this problem, we have decided to represent our ligand field potential using the so-called Angular Overlap Model (AOM), 37 inasmuch as in each computational step we are performing, its plausibility connected with chemical insight is given. The theory of AOM is also exhaustively explained elsewhere 37,38 and was applied thoroughly to describe the influence of the ligand field on either the 3d-orbital of the transition metal 37 or the 4f-orbital of lanthanide complexes.…”

Section: Methodsmentioning

confidence: 99%

“…To circumvent this problem, we have decided to represent our ligand field potential using the so-called Angular Overlap Model (AOM), 37 inasmuch as in each computational step we are performing, its plausibility connected with chemical insight is given. The theory of AOM is also exhaustively explained elsewhere 37,38 and was applied thoroughly to describe the influence of the ligand field on either the 3d-orbital of the transition metal 37 or the 4f-orbital of lanthanide complexes. 3 The AOM approach represents the 7 Â 7 H LF (f) and the 5 Â 5 H LF (d) ligand field matrices in terms of two different sets of e s and e p parameters for each ligand donor, weighted by factors depending to the angular position of the ligand in the coordination sphere of the Pr 3+ center.…”

Section: Methodsmentioning

confidence: 99%

Ligand field density functional theory calculation of the 4f2 → 4f15d1 transitions in the quantum cutter Cs2KYF6:Pr3+

Ramanantoanina

Urland

Cimpoesu³

et al. 2013

Phys. Chem. Chem. Phys.

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Herein we present a Ligand Field Density Functional Theory (LFDFT) based methodology for the analysis of the 4f n -4f nÀ1 5d 1 transitions in rare earth compounds and apply it for the characterization of the show that the occupation of the three undistorted sites allows a quantum-cutting process. However size effects due to the difference between the ionic radii of Pr 3+ and K + as well as Cs + lead to the distortion of the K + -and the Cs + -site, which finally exclude these sites for quantum-cutting. A detailed discussion about the origin of this distortion is also described.

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“…The splitting pattern of the orbitals can be easily rationalized within the angular overlap model (AOM). (1) e eq r and e eq p are AOM parameters for the equatorial nitrogen ligands refering to a standard orientation [31,32]. Since there is no poverlap within porphyrine plane the b 2g (d xy ) orbital has a non-bonding character.…”

Section: Ground State and Epr Spectra Of Copmentioning

confidence: 99%

A DFT based ligand field study of the EPR spectra of Co(II) and Cu(II) porphyrins

Atanasov

Daul

Rohmer

et al. 2006

Chemical Physics Letters

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. dedicate this work to the memory of late Prof. A. Schweiger. AbstractUsing a DFT based Ligand Field treatment (LFDFT) of the electronic structure of Co(II) and Cu(II) porphyrins (CoP and CuP) we analyse the origin of their EPR spectra. From a comparison between theoretical result on Co model clusters (CoP and CoP-ZnP dimer) we conclude that the g-tensor values are very sensitive to the axial coordination which stabilizes a 2 A 1 ground state in good agreement with experimental data. In contrast, DFT overestimates Cu-ligand covalency, leading to large discrepancy with experiments, and hence the orbital contribution to the computed g-values is too small. Using a numerical adjustment of nuclear charge for Cu, a good agreement between the computed and the experimental g-tensor values is observed. The influence of the DFT functional on the calculated g-tensor is also discussed.

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The angular overlap model, an attempt to revive the ligand field approaches

Cited by 433 publications

References 6 publications

Ligand field density functional theory for the prediction of future domestic lighting

Ligand field density functional theory for the prediction of future domestic lighting

Ligand field density functional theory calculation of the 4f2 → 4f15d1 transitions in the quantum cutter Cs2KYF6:Pr3+

A DFT based ligand field study of the EPR spectra of Co(II) and Cu(II) porphyrins

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