Theory of a coupled doublet-triplet system

Abstract
A theory of the magnetic dipolar interaction of a triplet state with a doublet state is presented. An effective spin hamiltonian, the spin functions and energy eigenvalues of the resulting doublet (S = 1/3), quartet (S = 3/2) and mixed doublet-quartet pair states are calculated. It is shown that the zero field and high field E.S.R. spectra are sensitively dependent on the energy separation ΔεDQ between the electronic doublet (D) and quartet (Q) states.