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Title

The electroaffinity of O2 by DFT and coupled MCSCF/perturbation approaches : a computational experiment

Authors
Giessner-Prettre, Claude
Published in Chemical Physics Letters. 1996, vol. 250, no. 2, p. 178-186
Abstract The electroaffinity of the O2 molecule is revisited using density functional theory (DFT) and perturbation treatments built on a MCSCF wavefunction that includes most of the non-dynamic correlation effects (MC/P approach). Using a standard 6–31 + G* basis set, DFT treatments based on BLYP or B3LYP functionals provide electroaffinities of the order of +0.6 eV that compare favorably to experiment. Coupled MCSCF/perturbation treatments using an Epstein-Nesbet partition of the molecular Hamiltonian give a more accurate value of +0.492 eV in excellent agreement with the most recent experimental data (+0.431 eV) as well as with highest-level purely variational ab initio treatments which are far less tractable for larger systems. The analysis of the results in terms of differential correlation effects made it possible to identify the failure of the previous MCSCF-limited treatments as arising from the dynamic correlation of the electron pair describing the σO---:O bond.
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Research group Groupe Weber
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PARISEL, Olivier, ELLINGER, Yves, GIESSNER-PRETTRE, Claude. The electroaffinity of O2 by DFT and coupled MCSCF/perturbation approaches : a computational experiment. In: Chemical Physics Letters, 1996, vol. 250, n° 2, p. 178-186. https://archive-ouverte.unige.ch/unige:2825

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Deposited on : 2009-09-21

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