Calculation of EPR transition fields and transition probabilities for a general spin hamiltonian

Applications of automatic fittings to powder EPR spectra of free radicals,S>1/2, and coupled systems

“…In spite of these complications, Herring et al [17] obtained almost perfect agreement between experimental and simulated spectra with the method in ref. 4. This radical has therefore served as a model in analyzing EPR spectra featuring large nuclear quadrupole interactions [19].…”

“…1-3, being based on perturbation theory. Methods on the basis of exact diagonalization of the spin Hamiltonian have been developed more recently and are now beginning to replace the perturbation methods [4][5][6][7]. The fitting to experimental spectra is typically made by adjustment of the coupling tensors until a best fit is obtained, normally by visual inspection.…”

Modeling EPR Powder Spectra Using Numerical Diagonalization of the Spin Hamiltonian

“…High-order perturbation calculations (16) or straightforward numerical diagonalization of the spin Hamiltonian (see, for instance, [17][18][19][20][21] are then required to determine reliable resonance fields values. For S Ͼ 3 2 , e.g., for S-state ions, the large number of allowed transitions occurring between and inside the Kramers' doublets, makes it difficult to index the EPR lines in powder studies (22,23), and even in single-crystal studies (24).…”

ESR of Cu2+ doped cadmium (II) formate dihydrate

“…A least squares fit [5] of the calculated and observed line positions gave the accurate magnetic parameters and their orientation relative to the frame ða p ; b; cÞ which in turn can be related to the crystal axes. If the symmetry was constrained to have axial nature, the rms error increases twenty times with a non-random distribution of errors.…”