DFT Calculations of EPR Parameters in an Ionic Lattice of [M(CN)₄]^3- (M = Ni, Pd, Fe, Ru, Os) Complexes

Abstract

The electronic g-tensor and hyperfine coupling constants were calculated for cyanide coordination complexes [M(CN)4]3- (M = Ni, Pd, Fe, Ru, Os) in KCl or NaCl host lattices through an embedded calculation approach using the Density Functional Theory and compared with previous experiments. For all tested complexes, the B3LYP functional is in good agreement with the experiments for the hyperfine coupling constants. For the electronic g-tensor calculations, performed using the coupled perturbed SCF theory, some discrepancies were found, and the best agreements with the experimental values were achieved by the B3LYP functional.

Defect Structures, Electronic Properties, UV–Vis, and EPR Parameters for Rh2+ Centers in LiD: A DFT Study

“…The density of states of Rh, D, and Li atoms are also calculated to further exhibit the electronic properties of the systems. Finally, the UV–Vis and EPR spectra are simulated with embedded cluster model in code ORCA (version 4.0), which show consistency with the experimental results.…”

DFT calculations of the defect structures, electronic structures, and EPR parameters for three Rh2+ centers in AgCl

“…Besides, in view of the analogous but slightly better g tensors based on the energy curves than the direction geometry optimization (see Table ), the energy curve optimization method seems a little more effective and applicable to others similar alkali halides with d 7 dopants. The discrepancies of the calculated g tensors from the experimental data can be discussed as follows. First, DFT theory usually provides EPR results of higher quality than HF‐based techniques, but there are still some discrepancies in our results with respect to the experimental data, possibly attributable to the imperfect treatments of the important relativistic effects (particularly the spin‐orbit coupling accounting for the last dominant terms of g and A tensors) for the involved heavy elements Rh and Ag Spin density transference from the lowest states of impurity Rh 2+ to the immediate lattice atoms is merely insufficiently represented in the embedded cluster model . For example, the electric charge (about 1.04 e) of central Rh 2+ is remarkably underestimated, whereas covalence and the strength of local crystal fields around Rh are overestimated, leading to the calculation errors for the resultant g tensor .…”

“…First, DFT theory usually provides EPR results of higher quality than HF-based techniques, but there are still some discrepancies in our results with respect to the experimental data, possibly attributable to the imperfect treatments of the important relativistic effects (particularly the spin-orbit coupling accounting for the last dominant terms of g and A tensors) for the involved heavy elements Rh and Ag [59] Spin density transference from the lowest states of impurity Rh 2+ to the immediate lattice atoms is merely insufficiently represented in the embedded cluster model. [60,61] For example, the electric charge (about 1.04 e) of central Rh 2+ is remarkably underestimated, whereas covalence and the strength of local crystal fields around Rh are overestimated, leading to the calculation errors for the resultant g tensor. [62] Meanwhile, the two-fold orbital degenerated ground 2 E g state for octahedral 4d 7 (Rh 2+ ) centers can induce extra errors in the DFT calculations.…”

Predicting ESR Peaks in the 4d and 5d Transition Metal Ion Complexes by NMR, ESR and NQR Parameters: A DFT Study

“…Only a limited research work had been done in the experimental determination of number of ESR peaks in complexes of 4d and 5d metal ions [1][2][3][4][5] like Zr (III) [6][7][8] ,Hf (III) [7][8][9] ; Nb (IV) [10][11][12] , Ta (IV) 9 ; Tc (II) 9, 13, 14 , Re (II ) [15][16][17] ; Ru (III) [18][19][20][21][22][23][24] , Os (III) [18][19][20]24 ; Rh (IV) 25-27 , Ir (IV) 26,27 which formed five congeners of 2 nd and 3 rd transition series.…”