Abstract
An approximate unrestricted Hartree-Fock method is used to calculate spin densities in the odd alternant radicals cyclohexadienyl, benzyl, perinaphthenyl and triphenylmethyl and the linear polyene radicals from allyl to C19H21. The results agree quite well with the exact calculations and with empirical estimates as well as with experimental data on hyperfine splitting constants and E.S.R. second moments.