Estimates of non-local corrections to total, ionisation, and single-particle energies

Total and ionisation energies have been calculated for a number of simple atoms using spin density functional theory in the local-spin-density approximation (LSDA) as well as by methods that attempt to correct it for electron self-interaction effects. The LSDA total energies using the new improved results of Vosko et al. (1980) for the correlation energy of a spin-polarised homogeneous electron gas are further from experiment than those based on other frequently used, but less accurate, parameterisations. On the other hand ionisation energies are improved and compare as well with experimental as the self-interaction corrected results. By using the transition-state concept the authors examine the non-local correction to the LSDA single-particle potential of a valence electron and show that it can be relatively large.