In: Physical Chemistry Chemical Physics, 2014, vol. 16, no. 24, p. 12282–12290
We discuss the applicability of the Angular Overlap Model (AOM) to evaluate the electronic structure of lanthanide compounds, which are currently the subject of incredible interest in the field of luminescent materials. The functioning of phosphors is well established by the f–d transitions, which requires the investigation of both the ground 4fn and excited 4fn−15d1 electron configurations...
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In: Chemical Physics Letters, 2013, vol. 588, p. 260–266
We present a recipe for the calculation of the optical properties of Ce³⁺-doped systems. The model implies the use of ligand field phenomenology in conjunction with Density Functional Theory (DFT). The particular procedures enable the reliable prediction of the 4f¹ → 4f⁰5d¹ transitions in Cs₂NaYCl₆:Ce³⁺. The analysis of the doping of Ce³⁺ into the host is accomplished by band...
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In: Inorganic Chemistry, 2016, vol. 55, no. 14, p. 6853–6860
Detailed experimental data on UPO₄Cl comprising single-crystal UV/vis/NIR spectra and temperature-dependent magnetic susceptibilities form the basis for the investigation of the electronic structure of the U⁴⁺ cation in UPO₄Cl. For modeling of the observed physical properties the angular overlap model (AOM) was successfully employed. The computations were performed using the...
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In: Molecular Physics, 2015, vol. 113, no. 13-14, p. 1712-1727
A series of computational experiments performed with various methods belonging to wave-function and density functional theories approaches the issue of bonding regime and exchange coupling in the title compounds. Gd₂@C₈₀ is computed with a very weak exchange coupling, the sign depending on the method, while Gd₂@C₇₉N has resulted with a strong coupling and ferromagnetic ground...
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In: Inorganic Chemistry, 2015, vol. 54, no. 11, p. 5504–5511
Single crystals of uranium(IV)-containing A₂USi₆O₁₅ (A = K, Rb) were grown using the flux growth method. The two compounds crystallize in a new structure type related to Cs₂USi₆O₁₅. K₂USi₆O₁₅ exhibits an interesting crystal-to-crystal transition, which is accompanied by an intense color change. Magnetic properties are reported for A₂USi₆O₁₅ and differ from other...
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In: Physical Chemistry Chemical Physics, 2013, vol. 15, no. 33, p. 13902–13910
Herein we present a Ligand Field Density Functional Theory (LFDFT) based methodology for the analysis of the 4fⁿ → 4fⁿ⁻¹5d¹ transitions in rare earth compounds and apply it for the characterization of the 4f² → 4f¹5d¹ transitions in the quantum cutter Cs₂KYF₆:Pr³⁺ with the elpasolite structure type. The methodological advances are relevant for the analysis and prospection of...
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In: Physical Chemistry Chemical Physics, 2014, vol. 16, no. 28, p. 14625–14634
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...
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In: Chemical Physics Letters, 2015, vol. 622, p. 120–123
The theoretical rationalization of the open-shell 4f and 5d configuration of Eu²⁺ is by far not trivial because it involves a non-standard version of ligand field theory, based on a two-shell Hamiltonian. Here we present our methodology based on ligand field theory, taking the system CsCaBr₃:Eu²⁺ as a case study with an octahedral coordination sphere of Eu²⁺. The ligand field,...
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In: Physical Chemistry Chemical Physics, 2016, vol. 18, no. 19, p. 13196–13208
The Yb²⁺-doped perovskite derivatives CsMX₃ (M = Ca and Sr; X = Cl, Br, and I) are ideal systems for obtaining a detailed insight into the structure–luminescence relationship of divalent lanthanides. The investigation of the respective photoluminescence properties yielded two emission bands in the violet and blue spectral range for all compounds, which are assigned to the spin-allowed...
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In: Chemical Physics Letters, 2015, vol. 620, p. 29–34
In this work, we predict and measure the optical behaviour of Pr³⁺ in different binary and ternary fluorides. We use a validated model based on Ligand Field Theory and Density Functional Theory to calculate the multiplet energy levels arising from the ground [Xe]4f² and excited [Xe]4f¹5d¹ electron configurations of Pr³⁺ in its chemical environment. Moreover, the luminescence spectra of...
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