Abstract
Second order perturbation solutions are given to the general experimental hamiltonian : where the axes of the g, D and A tensors may be non-collinear. The effects of the non-collinearities are discussed in terms of the modifications of the E.S.R. parameters for both single crystal and polycrystalline samples. The principles are illustrated for the E.S.R. of the formyl radical from published single crystal and powder data.