Species with negative electron affinity and standard DFT methods. Finding the valence anions

M. PUIATTI; D. M. A. VERA *; A. B. PIERINI

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

The Royal Society of Chemistry (RSC)

Lugar: London; Año: 2008 vol. 10 p. 1394 - 1399

1463-9076

Recently, we have shown that traditional bound-electron DFT models are reliable enough to reproduce negative electron affinities (EA) within a few meV, as long as the valence anion state is found, but they seem to fail in predicting the lowest EA when the ground anion state obtained is non-valence, which holds the extra electron in a diffuse orbital around the molecule; here we propose an alternative approach for finding the valence anion state, based on the stabilization exerted by a polar solvent; the methodology yields correct EA values (i.e. beyond the Koopmans´ theorem approximation) by gradually decreasing the dielectric constant of the medium.