On quasi-transferable molecular fragments. Part V: Free radicals; the dissociation of organic molecules, an improved Xα(LSD) approach

► The notion of ”quasi-transferable fragments” applies to molecules and radicals. ► The new formula for ΔHf° based on these fratgments thus stands for radicals as well. ► A modified Xα(LSD) method is shown to yield accurate enthalpies of formation, ΔHf°. ► Xαresults and the new formula for ΔHf° cast light on the bonding in free radicals.