Can the electron magnetic resonance (EMR) techniques measure the crystal (ligand) field parameters?

Alternative zero-field splitting (ZFS) parameter sets and standardization for Mn2+ ions in various hosts exhibiting orthorhombic site symmetry

“…triclinic, site symmetry the spin Hamiltonian, including the Zeeman electronic (Ze) terms and ZFS ones in the ES operators notation [3,19,32], is defined by [1][2][3][4][5]: …”

“…(1) upon replacement of the spin operator S by the angular momentum L or J [1][2][3][4][5]. Therefore, the standardization idea can also be applied to an orthorhombic H CF .…”

“…This confusion is widely spread in EMR literature as reviewed in [3][4][5] as well as in magnetism literature as reviewed more recently in [63,64]. Instances of the CF=ZFS confusion are evident in several phrases in [60], e. Both systems exhibit monoclinic space group symmetry and thus a suitably modified CAS*, i.e.…”

“…While proper terminology was used for the 'zero-field splitting parameters' D and E, the parameter a was named confusingly [3,5,62] as "the cubic crystal field parameter 'a'." For the "biquadratic term", i.e.…”

“…The latter Hamiltonian is often confused in EMR literature with the crystal-field (CF) Hamiltonian, in spite of their physically different nature [5]. The standardization idea has originally been introduced in EMR area for the second-rank conventional ZFS terms based on the observation that the ratio of the orthorhombic (E) to axial (D) ZFS parameters (ZFSPs): λ = E/D can always be limited to the range (0, ± 1/3) by appropriate choice of coordinate system [6,7,8].…”