First ionisation potentials of atoms obtained with local-density schemes

The first ionisation potentials of the light atoms up to krypton are computed by means of Slater's transition-state method for the following local-density functional models: Slater's exchange potential, the X alpha and X alpha beta methods and the exchange correlation potential due to Hedin and Lundqvist (1972). By taking into account the experimental multiplet structure of the atoms and the corresponding ions, a direct comparison can be made between experiment and theory. For the four potential models, this shows systematic trends, which are explained. In addition, comparison is made with Hartree-Fock results. It is concluded that the best overall agreement is found for the Hedin-Lundqvist potential.