Configuration Energies of the d-Block Elements

Configuration energies (CE) of the d-block elements (Groups 3−11) are electronegativities evaluated from the formula CE = ( p ε s + q ε d )/( p + q ). ε s and ε d are the multiplet-averaged one-electron energies of the s- and d-orbitals of atoms which are in the lowest energy of the configurations s n d m and s n - 1 d m +1, and whose highest known oxidation state is ( p + q ). The orbital energies are obtained from spectroscopic data. Configuration energies generally increase across a row, with the highest values occurring at nickel, silver, and gold; all are lower than the CE of silicon, the least electronegative nonmetal (except for gold which has a CE equal to that of silicon). Down the groups configuration energies invariably decrease from the first row to the second row; for Groups 7−12, the third-row element has a CE higher than that of the second-row element, due to increasing relativistic stabilization of the 6s orbitals.