The spin Hamiltonian for electron spin resonance of radicals in doublet states: calculations in the energy weighted maximum overlap model

The parameters of a spin Hamiltonian for the description of electron spin resonance spectra of oriented radicals, trapped in crystalline solids, are described within an approximate electron propagator framework. Only radicals in doublet states are considered, so that the pertinent parameters are the g-tensor, the hyperfine interaction tensor and the quadrupole interaction tensor. Various semiempirical approaches are discussed and a number of calculations are carried out in the energy weighted maximum overlap model (e. w. m. o.). Particularly satisfactory results were obtained for the g-tensors and ‘central’ atom hyperfine interaction tensors.