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

Abstract

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.

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

“…[47][48][49] The LFDFT calculations were achieved following the detailed procedure already described in ref. 32 where the most important step consists to the representation of the density in a totally symmetric form using the approach of the AOC type calculation. Matlab/Octave codes for the LFDFT program together with the determination of the Wybourne-normalized crystal field parameters from the ligand field matrix are available from the authors upon request.…”

“…31 This multideterminental approach is based on the average of configuration (AOC) occupation of the KohnSham orbital, when we are dealing with single-open-shell configurations. This procedure was recently extended to account for two-open-shell f and d electrons, 32 and has produced a good prediction of the f -d transitions in Ce 3+ and Pr 3+ -doped compounds. 32,33 The crystal structures with fluoride ligands are mostly suitable for inorganic phosphor candidates due to their relative stability and their ability to avoid phonons upon the f -d transitions, 6 ergo to dismiss radiationless transitions.…”

“…This procedure was recently extended to account for two-open-shell f and d electrons, 32 and has produced a good prediction of the f -d transitions in Ce 3+ and Pr 3+ -doped compounds. 32,33 The crystal structures with fluoride ligands are mostly suitable for inorganic phosphor candidates due to their relative stability and their ability to avoid phonons upon the f -d transitions, 6 ergo to dismiss radiationless transitions. While the Pr 3+ ion is doped into certain fluoride host lattices, a particular yet interesting optical phenomenon is experimentally observed, the so-called quantum cutting process.…”

“…In the extension of our previous work detailing the non-empirical prediction of the 4f n -4f nÀ1 5d 1 transitions, 32 we present in this paper supplementary tools for a better parameterization of the inter-electron repulsion interaction in the ligand field theory Hamiltonian. Previously, we have extracted the Slater-Condon parameters by least squares fit from the energies of the 231 Slaterdeterminants originating from the 4f 2 (91 microstates) and 4f 1 5d 1 electron configurations (140 microstates) of Pr 3+ , where we have misrepresented the energies of some spectral terms, as stressed in ref.…”

“…Previously, we have extracted the Slater-Condon parameters by least squares fit from the energies of the 231 Slaterdeterminants originating from the 4f 2 (91 microstates) and 4f 1 5d 1 electron configurations (140 microstates) of Pr 3+ , where we have misrepresented the energies of some spectral terms, as stressed in ref. 32. In the present work, we consider the determination of the Slater-Condon parameters directly from the radial functions of the 4f and 5d Kohn-Sham orbitals.…”