Comparative analysis of the microscopic spin-Hamiltonian expressions used for the non-Kramers Fe2+(3d6) ions with spin S=2 in reduced rubredoxin, desulforedoxin, and related systems

Comparative Analysis of Experimental and Theoretical Zero-Field Splitting and Zeeman Electronic Parameters for Fe2+ Ions in FeX2·4H2O (X = F, Cl, Br, I) and [Fe(H2O)6](NH4)2(SO4)2

“…This study shows the usefulness of the MSH/VBA package [8,9], which enables: (i) comprehensive modeling of the spin Hamiltonian parameters SHPs for 3d 4 and 3d 6 (S = 2) ions at orthorhombic and tetragonal symmetry sites, (ii) consideration of wide ranges of values of the microscopic parameters, i.e. the spin-orbit (SO: λ), spin-spin (SS: ρ) coupling constants, and the crystal-field (ligand-field) energy levels (∆ i ) within the 5 D multiplet, (iii) determination of the dependence of the ZFS parameters b q k (in the Stevens notation) and the Zeeman factors g i on λ, ρ, and ∆ I as well as presentation of results on suitable graphs, (iv) consideration of the role of SO (λ) and SS (ρ) coupling contributions, (v) investigations of the role of the fourth-rank ZFS terms, and (vi) comparison with DFT/ab initio results.…”

“…[15], MSH modeling is carried out using the MSH/VBA program [8,9] for the orthorhombic case #1 (αOI1) [28] and various sets of the microscopic input parameters: the spin-orbit (λ) and spin-spin (ρ) coupling constants, the crystal-field (ligand-field) energy levels (∆ i ) within the 5 D multiplet (see Fig. 2 Table I).…”

“…2 Table I). The respective standardization transformations Sx, x = 2 to 6 are defined in [8,[21][22][23], whereas S1 denotes the already standard sets.…”

“…Similar modeling, using the package MSH/VBA [8,9] based on the microscopic spin Hamiltonian (MSH) approach, has recently been undertaken for [Fe(H 2 O) 6 ](NH 4 ) 2 (SO4) 2 (FASH) [10][11][12]. The microscopic SH (MSH) approach incorporates MSH expressions for the ZFS and Ze parameters up to fourth-order perturbation theory suitable for of 3d 4 and 3d 6 ions with spin S = 2 at orthorhombic and tetragonal symmetry sites in crystals, which exhibit an orbital singlet ground state arising from the ground 5 D multiplet [8,9]. The aim of this paper is to provide a comparative analysis of experimental and theoretical ZFS and Ze parameters for Fe 2+ ions in FeCl 2 ·4H 2 O [3] and FASH.…”

Implications of Invalid Conversions between Crystal-Field Parameters and Zero-Field Splitting Ones Used in Superposition Model

“…Various types of terminological confusions between the CF (LF), SH (ZFS), and related quantities, identied so far in literature have been discussed in the reviews [5,6,15] and most recently [14]. For the background theory and notations, * corresponding author; e-mail: crudowicz@zut.edu.pl which illustrate the actual nature of the interrelationships between the CF parameters (CFPs) and the ZFS parameters (ZFSPs) and enable subsequent clarications, the readers are advised to consult the review [14].…”