HIGH-SPIN ZEEMAN TERMS IN THE SPIN HAMILTONIAN

Discussion and relevant tables are presented for the expression of the general spin Hamiltonian in terms of multiple-vector (B, S, I) spherical tensors,k and their resolution into products of single-vector spherical tensors. An improved notation is presented for terms in the EPR spin Hamiltonian linear and quadratic in applied magnetic field B, and of degrees up to five in electron spin S. The new notation is an extension of an existing one for zero-field terms, resulting in the following properties: previously published site-symmetry rules for zero-field parameters and previously published rules for the effects of axis system transformations on zero-field parameters can be applied directly to parameters defined in the equations and tables herein; the use of a spherical-tensor formalism results in parameter sets within which there are no redundancies. No previously published notations possess all these useful properties. Relations are given between spin-Hamiltonian parameters in the proposed notation and those in previous notations. An indication is given as to how the notation can be extended to other terms of the spin Hamiltonian, including terms involving nuclear spins. © 1990.