Loading...
Improving the Accuracy of Density Functional Approximations: Self-Interaction Correction and Random Phase Approximation
Ruan, Shiqi
Ruan, Shiqi
Citations
Altmetric:
Genre
Thesis/Dissertation
Date
2022
Advisor
Committee member
Group
Department
Physics
Permanent link to this record
Collections
Research Projects
Organizational Units
Journal Issue
DOI
http://dx.doi.org/10.34944/dspace/8312
Abstract
Complexes containing a transition metal atom with a 3d^4 - 3d^7 electron configuration typically have two low-lying, high spin (HS) and low spin (LS) states. The adiabatic energy difference between these states, known as the spin-crossover energy, is small enough to pose a challenge even for electronic structure methods that are well known for their accuracy and reliability. In this work we analyze the quality of electronic structure approximations for spin-crossover energies of iron complexes with four different ligands by comparing energies from self-consistent and post-self-consistent calculations for methods based on the random phase approximation and the Fermi-L\"{o}wdin self-interaction correction. Considering that Hartree-Fock densities were found by Song et al. J. Chem. Theory Comput. 14,2304 (2018) to eliminate the density error to a large extent, and that the Hartree-Fock method and the Perdew-Zunger-type self-interaction correction share some physics, we compare the densities obtained with these methods to learn about their resemblance. We find that evaluating non-empirical exchange-correlation energy functionals on the corresponding self-interaction-corrected densities can mitigate the strong density errors and improves the accuracy of the adiabatic energy differences between HS and LS states.
Description
Citation
Citation to related work
Has part
ADA compliance
For Americans with Disabilities Act (ADA) accommodation, including help with reading this content, please contact scholarshare@temple.edu