Abstract
The magnetic resonance of a spin-half system in a static field and an arbitrarily oriented oscillating field has been studied recently by McClean and Swain (1976) by a continued-fraction technique in quantum-electrodynamical perturbation theory, a difficult procedure involving twenty fourth-order processes and some rather heavy analysis. It is shown how the semiclassical approach of Pegg and Series (1970, 1973) yields the same results more simply. This approach also has the advantage of being applicable to systems of arbitrary spin.