The results of calculations of doubler state G tensors of organic radicals often show unsatisfactory agreement with the respective experimental data. This led us to reconsider the results of the Rayleigh-Schrodinger perturbation theory approach found in the literature. We came to the conclusion that neither the expressions given for restricted nor for unrestricted Hartree-Fock functions are fully correct. In this paper new expressions for the G tensor to be used with restricted Hartree-Fock functions will be introduced and results of calculations employing these new formulas in conjunction with molecular states from semiempirical Hartree-Fock-type calculations are discussed. (C) 1997 American Institute of Physics.