Calculation of temporary anion states using density functional theory

Density functional theory (DFT) was examined for computing energies of temp orary anions having negative electron affinities ranging from - 8.0 to - 0. 2 eV. The calculated electron affinities are in good agreement with experim ent for rr states and low-energy sigma* states. The dependence of the DFT r esults on basis set was investigated. Comparisons are made with results fro m traditional ab initio molecular orbital theory based on Koopmans' theorem (KT) and energy difference methods (Delta HF and Delta MP2). It is shown t hat DFT methods provide an improvement over use of ab initio molecular orbi tal methods. (C) 1999 Published by Elsevier Science B.V. All rights reserve d.