In: Inorganic Chemistry, 2015, vol. 54, no. 17, p. 8319–8326
The most efficient way to provide domestic lighting nowadays is by light-emitting diodes (LEDs) technology combined with phosphors shifting the blue and UV emission toward a desirable sunlight spectrum. A route in the quest for warm-white light goes toward the discovery and tuning of the lanthanide-based phosphors, a difficult task, in experimental and technical respects. A proper theoretical...
|
In: Physical Chemistry Chemical Physics, 2015, vol. 17, no. 28, p. 18547–18557
Ligand field density functional theory (LFDFT) is a methodology consisting of non-standard handling of DFT calculations and post-computation analysis, emulating the ligand field parameters in a non-empirical way. Recently, the procedure was extended for two-open-shell systems, with relevance for inter-shell transitions in lanthanides, of utmost importance in understanding the optical and magnetic...
|
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...
|
In: Physical Chemistry Chemical Physics, 2015, vol. 17, no. 14, p. 9116–9125
We present a theoretical work detailing the electronic structure and the optical properties of (PrF₈)⁵⁻ embedded in LiYF₄, complementing the insight with data that are not available by experimental line. The local distortions due to the embedding of the lanthanide ion in the sites occupied in the periodic lattice by smaller yttrium centres, not detectable in regular X-ray analyses, are...
|
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,...
|
In: Physical Chemistry Chemical Physics, 2014, vol. 16, no. 23, p. 11337–11348
Considering the DySc₂N@C₈₀ system as a prototype for Single Ion Magnets (SIMs) based on endohedral fullerenes, we present methodological advances and state-of-the art computations analysing the electronic structure and its relationship with the magnetic properties due to the Dy(III) ion. The results of the quantum chemical calculations are quantitatively decrypted in the framework of ligand...
|
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...
|
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...
|
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...
|
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...
|