g-Tensor calculations of bicyclic 1,3,2-dithiazolyl radicals using the coupled-perturbed Kohn–Sham UB1LYP and UPBE0 hybrid density functionals

The g tensor components of selected bicyclic 1,3,2-dithiazolyl radicals of C2v symmetry are computed by the coupled-perturbed Kohn–Sham hybrid density functional techniques. Their values are in very good agreement with those determined experimentally (within 140–750 ppm). When compared to the unrestricted Hartree–Fock (HF) method, the inclusion of electron exchange and correlation, via the UB1LYP and UPBE0 functionals, improves the agreement between theory and experiment. Thus, for the first time, g tensors of this class of radicals are accurately calculated without using post HF techniques. Also, the first and second order contributions to the g tensors are separated and analyzed.