The optimized effective potential and the self-interaction correction in density functional theory: Application to molecules

Journal Article · Mon May 08 04:00:00 EDT 2000 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.481421· OSTI ID:20216291

Garza, Jorge ^[1]; Nichols, Jeffrey A ^[2]; Dixon, David A ^[2]

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1. Departamento de Quimica, Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana-Iztapalapa. A.P. 55-534, Mexico Distrito Federal 09340, (Mexico)
2. Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)

The Krieger, Li, and Iafrate approximation to the optimized effective potential including the self-interaction correction for density functional theory has been implemented in a molecular code, NWChem, that uses Gaussian functions to represent the Kohn and Sham spin-orbitals. The differences between the implementation of the self-interaction correction in codes where planewaves are used with an optimized effective potential are discussed. The importance of the localization of the spin-orbitals to maximize the exchange-correlation of the self-interaction correction is discussed. We carried out exchange-only calculations to compare the results obtained with these approximations, and those obtained with the local spin density approximation, the generalized gradient approximation and Hartree-Fock theory. Interesting results for the energy difference (GAP) between the highest occupied molecular orbital, HOMO, and the lowest unoccupied molecular orbital, LUMO, (spin-orbital energies of closed shell atoms and molecules) using the optimized effective potential and the self-interaction correction have been obtained. The effect of the diffuse character of the basis set on the HOMO and LUMO eigenvalues at the various levels is discussed. Total energies obtained with the optimized effective potential and the self-interaction correction show that the exchange energy with these approximations is overestimated and this will be an important topic for future work. (c) 2000 American Institute of Physics.

• OSTI ID: 20216291
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 18 Vol. 112; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CORRECTIONS
ELECTRONIC STRUCTURE
MOLECULAR ORBITAL METHOD
MOLECULES
OPTIMIZATION
POTENTIALS
THEORETICAL DATA