C. Rudowicz et Sk. Misra, Spin-Hamiltonian formalisms in electron magnetic resonance (EMR) and related spectroscopies, APPL SP REV, 36(1), 2001, pp. 11-63
The historical development leading to, and the current status of, the spin-
Hamiltonian (SH) formalisms. characterizing electron magnetic resonance (EM
R), also referred to as electron paramagnetic (or spin) resonance (EPR or E
SR), is reviewed. The spin-Hamiltonian concept is briefly outlined to set a
framework for definitions of relevant terms. Meanings of the terms which a
re often confused with each other, e.g. physical versus effective Hamiltoni
an, real versus effective versus fictitious spin, microscopic SH (MSH), zer
o-field-splitting (ZFS) Hamiltonian, generalized SH (GSH), and phenomenolog
ical SH (PSH), are elucidated. Various general approaches to 'derive' MSH a
s well as to 'construct' GSH for transition ions are discussed, This enable
s clarification of relationship between the ZFS Hamiltonian and (a) the cry
stal-field (CF), (b) electronic spin-spin, and (c) nuclear-quadrupole Hamil
tonians. The inadmissibility of the odd-order ZFS terms (1 = 3, 5) is also
discussed, A brief general classification of the major operator and paramet
er notations used in the literature to describe ZFS Hamiltonian is provided
. Other important areas relevant to EMR, where the SH concept plays a centr
al role, are outlined.