On the possible presence of odd-order terms in a magnetic resonance spin Hamiltonian for S-state ions

Abstract

It is argued that the recent admission of the zero-field splitting and the higher-order Zeeman terms of odd order into the spin hamiltonian for S-state ions is incorrect. The admission appears to be based on misconceptions concerning the nature of 'spin' in the case of S-state ions and a confusion of the states of an actual Hamiltonian and an effective (spin) Hamiltonian.