Abstract
Mathematical expressions for the electronegativities of the elements are derived exactly using the Hartree–Fock–Slater equations and Mulliken’s definition of electronegativity. Relaxation effects are neglected. These equations are the same ones used by Bartolotti, Gadre, and Parr. They are generalized for the spin-polarized case and calculations are done for the elements helium to krypton. Results show that the spin-polarized ionization potentials are closer to experiment than the non-spin-polarized ones and that the trend in the electronegativities obtained from spin-polarized calculations is the same as the one obtained by Bartolotti et al. using a non-spin-polarized program.