UB1LYP as an accurate and efficient method for computing the isotropic hyperfine tensor components of neutral bicyclic and tricyclic dithiazole radicals

The isotropic hyperfine tensor components (aiso) of six neutral mono-, bi- and tricyclic dithiazole radicals are computed using the UB1LYP hybrid density functional method. They are in very good quantitative agreement with those determined experimentally by EPR spectroscopy (<0.47 G). Thus, for the first time, aiso of large bi- and tricyclic hetero-radicals that contain sulfur linked to nitrogen are accurately calculated without resorting to post-Hartree–Fock techniques. As predicted, the computed hyperfine tensors show that these C2v molecules have no magnetically equivalent atoms [1].