Comments on57Fe Mössbauer spectra for Kramers doublets: A phenomenological interpretation

A static effective spinS=1/2 Hamiltonian is usually specified by a phenomenonological parameter, set, but the typical choice of parameters could be inappropriate. Two main issues are addressed: (i) Which spin Hamiltonian parameters are observable at a given applied field strength, and (ii) how should one deal with skewsymmetric components of the electronic Zeeman and magnetic hyperfine tensors that can be present for spin-coupled multinuclear complexes. Certain Mössbauer experiments were selected, somewhat arbitrarily, as examples; this analysis can be applied to other spectroscopic techniques as well.