The ground state optimized structures of some radical adducts of alpha-phenyl-N-tert-buthyl nitrone (PBN) in water and benzene solutions were calculated by using DFT ( B3LYP, B3PW91 and PBEPBE) and HF methods with 6-311++G(d, p), 6-31G(d, p) and LanL2DZ levels. As trapped radicals, F, Cl, Br, H, OH, CN, NCO, and N-3 were used. The calculated isotropic hyperfine coupling constants of all the trapped radicals were seen to be in good agreement with the corresponding experimental data. The hyperfine coupling constant due to the beta proton of nitroxide radical was seen to be effected with the opposite spin density of oxygen nucleus bonded to the nitrogen. From all the calculated data it was concluded that for hyperfine calculations the DFT method is superior relative to the HF method. Also the geometrical parameters for the ground state optimized structures of all the radical adducts were listed, and the binding energies of all the trapped radicals were obtained. (C) 2014 Elsevier B.V. All rights reserved.