Odd-even alternation of global hardnesses in the Nan (n=2-9) clusters

Ionization potentials, electron affinities, sind global hardnesses have been computed for clusters of sodium ranging from two to nine atoms, at nonlocal density functional level, with the aim to verify the occurrence of the odd-even alternation rule. The hardnesses, as well as the ionization potentials and the electron affinities, assume alternatively high and low values in correspondence of closed- and open;shell systems, respectively. (C) 2000 John Wiley & Sons, Inc.