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

## Abstract

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 formore »

- Authors:

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

- Publication Date:

- OSTI Identifier:
- 20216291

- Resource Type:
- Journal Article

- Journal Name:
- Journal of Chemical Physics

- Additional Journal Information:
- Journal Volume: 112; Journal Issue: 18; Other Information: PBD: 8 May 2000; Journal ID: ISSN 0021-9606

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 74 ATOMIC AND MOLECULAR PHYSICS; POTENTIALS; MOLECULES; ELECTRONIC STRUCTURE; OPTIMIZATION; CORRECTIONS; MOLECULAR ORBITAL METHOD; THEORETICAL DATA

### Citation Formats

```
Garza, Jorge, Nichols, Jeffrey A., and Dixon, David A.
```*The optimized effective potential and the self-interaction correction in density functional theory: Application to molecules*. United States: N. p., 2000.
Web. doi:10.1063/1.481421.

```
Garza, Jorge, Nichols, Jeffrey A., & Dixon, David A.
```*The optimized effective potential and the self-interaction correction in density functional theory: Application to molecules*. United States. doi:10.1063/1.481421.

```
Garza, Jorge, Nichols, Jeffrey A., and Dixon, David A. Mon .
"The optimized effective potential and the self-interaction correction in density functional theory: Application to molecules". United States. doi:10.1063/1.481421.
```

```
@article{osti_20216291,
```

title = {The optimized effective potential and the self-interaction correction in density functional theory: Application to molecules},

author = {Garza, Jorge and Nichols, Jeffrey A. and Dixon, David A.},

abstractNote = {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.},

doi = {10.1063/1.481421},

journal = {Journal of Chemical Physics},

issn = {0021-9606},

number = 18,

volume = 112,

place = {United States},

year = {2000},

month = {5}

}