Towards an Optimal Gradientdependent Energy Functional of the PZSIC Form
Results of Perdew–Zunger selfinteraction corrected (PZSIC) density functional theory calculations of the atomization energy of 35 molecules are compared to those of highlevel quantum chemistry calculations. While the PBE functional, which is commonly used in calculations of condensed matter, is known to predict on average too high atomization energy (overbinding of the molecules), the application of PZSIC gives a large overcorrection and leads to significant underestimation of the atomization energy. The exchange enhancement factor that is optimal for the generalized gradient approximation within the KohnSham (KS) approach may not be optimal for the selfinteraction corrected functional. The PBEsol functional, where the exchange enhancement factor was optimized for solids, gives poor results for molecules in KS but turns out to work better than PBE in PZSIC calculations. The exchange enhancement is weaker in PBEsol and the functional is closer to the local density approximation. Furthermore, the drop in the exchange enhancement factor for increasing reduced gradient in the PW91 functional gives more accurate results than the plateaued enhancement in the PBE functional. A step towards an optimal exchange enhancement factor for a gradient dependent functional of the PZSIC form is taken by constructing an exchange enhancement factor that mimics PBEsol formore »
 Authors:

^{[1]};
^{[2]};
^{[3]}
 Aalto Univ., Espoo (Finland). Dept. of Applied Physics
 Aalto Univ., Espoo (Finland). Dept. of Applied Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
 Aalto Univ., Espoo (Finland). Dept. of Applied Physics; Univ. of Iceland, Reykjavik (Iceland). Faculty of Physical Sciences
 Publication Date:
 Grant/Contract Number:
 AC0205CH11231
 Type:
 Accepted Manuscript
 Journal Name:
 Procedia Computer Science
 Additional Journal Information:
 Journal Volume: 51; Journal Issue: C; Journal ID: ISSN 18770509
 Publisher:
 Elsevier
 Research Org:
 Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
 Sponsoring Org:
 USDOE
 Country of Publication:
 United States
 Language:
 English
 Subject:
 density functional theory; selfinteraction correction; exchangecorrelation functional
 OSTI Identifier:
 1208605
Jónsson, Elvar Örn, Lehtola, Susi, and Jónsson, Hannes. Towards an Optimal Gradientdependent Energy Functional of the PZSIC Form. United States: N. p.,
Web. doi:10.1016/j.procs.2015.05.417.
Jónsson, Elvar Örn, Lehtola, Susi, & Jónsson, Hannes. Towards an Optimal Gradientdependent Energy Functional of the PZSIC Form. United States. doi:10.1016/j.procs.2015.05.417.
Jónsson, Elvar Örn, Lehtola, Susi, and Jónsson, Hannes. 2015.
"Towards an Optimal Gradientdependent Energy Functional of the PZSIC Form". United States.
doi:10.1016/j.procs.2015.05.417. https://www.osti.gov/servlets/purl/1208605.
@article{osti_1208605,
title = {Towards an Optimal Gradientdependent Energy Functional of the PZSIC Form},
author = {Jónsson, Elvar Örn and Lehtola, Susi and Jónsson, Hannes},
abstractNote = {Results of Perdew–Zunger selfinteraction corrected (PZSIC) density functional theory calculations of the atomization energy of 35 molecules are compared to those of highlevel quantum chemistry calculations. While the PBE functional, which is commonly used in calculations of condensed matter, is known to predict on average too high atomization energy (overbinding of the molecules), the application of PZSIC gives a large overcorrection and leads to significant underestimation of the atomization energy. The exchange enhancement factor that is optimal for the generalized gradient approximation within the KohnSham (KS) approach may not be optimal for the selfinteraction corrected functional. The PBEsol functional, where the exchange enhancement factor was optimized for solids, gives poor results for molecules in KS but turns out to work better than PBE in PZSIC calculations. The exchange enhancement is weaker in PBEsol and the functional is closer to the local density approximation. Furthermore, the drop in the exchange enhancement factor for increasing reduced gradient in the PW91 functional gives more accurate results than the plateaued enhancement in the PBE functional. A step towards an optimal exchange enhancement factor for a gradient dependent functional of the PZSIC form is taken by constructing an exchange enhancement factor that mimics PBEsol for small values of the reduced gradient, and PW91 for large values. The average atomization energy is then in closer agreement with the highlevel quantum chemistry calculations, but the variance is still large, the F2 molecule being a notable outlier.},
doi = {10.1016/j.procs.2015.05.417},
journal = {Procedia Computer Science},
number = C,
volume = 51,
place = {United States},
year = {2015},
month = {6}
}