The Fermi–Löwdin self-interaction correction for ionization energies of organic molecules
Abstract
(Semi)-local density functional approximations (DFAs) suffer from self-interaction error (SIE). When the first ionization energy (IE) is computed as the negative of the highest-occupied orbital (HO) eigenvalue, DFAs notoriously underestimate them compared to quasi-particle calculations. The inaccuracy for the HO is attributed to SIE inherent in DFAs. We assessed the IE based on Perdew–Zunger self-interaction correction on 14 small to moderate-sized organic molecules relevant in organic electronics and polymer donor materials. Although self-interaction corrected DFAs were found to significantly improve the IE relative to the uncorrected DFAs, they overestimate. However, when the self-interaction correction is interiorly scaled using a function of the iso-orbital indicator zσ, only the regions where SIE is significant get a correction. We discuss these approaches and show how these methods significantly improve the description of the HO eigenvalue for the organic molecules.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 10, 2020
- Source ID
- 10.1063/5.0024776
Entities
People
- Adrienn Ruzsinszky
- Biswajit Santra
- Koblar Alan Jackson
- Niraj K Nepal
- Puskar Bhattarai
- Santosh Adhikari
- Shiqi Ruan
Organizations
- Central Michigan University
- National Science Foundation
- Temple University
- United States Department of Energy