A semi-empirical calculation of hydrogen hyperfine coupling constants in some sigma electron radicals

Spin density distributions in a number of sigma electron radicals have been computed, using the unrestricted Hartree-Fock (UHF) [1] method with the CNDO/2 [2] approximations for the integrals involved. Coupling constants were calculated using simple relationships, and the results in general show good agreement with experiment. Similar calculations on fluorine containing radicals were performed, but core electrons need to be included explicitly to obtain meaningful results.