Local spin-density calculations of anisotropic hyperfine constants in oriented free radicals

Abstract The isotropic and anisotropic proton hyperfine tensors in malonic and glutaconic acid radicals have been calculated from first principles, using the spin-polarized discrete variational Xα method (DVM). The calculated values are found to be in good agreement (≲20%) with the results of ESR and ENDOR experiments. The sensitivity of the hyperfine constants to molecular conformation has been examined by calculations at several different geometries.