A widely used approximation to the exchange-correlation functional in density functional theory is the local density approximation (LDA), typically derived from the properties of the homogeneous electron gas (HEG). We previously introduced a set of alternative LDAs constructed from one-dimensional systems of one, two, and three electrons that resemble the HEG within a finite region. We now construct a HEG-based LDA appropriate for spinless electrons in one dimension and find that it is remarkably similar to the finite LDAs. As expected, all LDAs are inadequate in low-density systems where correlation is strong. However, exploring the small but significant differences between the functionals, we find that the finite LDAs give better densities and energies in high-density exchange-dominated systems, arising partly from a better description of the self-interaction correction.
|Number of pages||8|
|Journal||Physical Review B|
|Publication status||Published - 25 Jun 2018|
Bibliographical note©2018 American Physical Society
Comparison of local density functionals based on electron gas and finite systems
Godby, R. W. (Supervisor), Entwistle, M. (Creator) & Casula, M. (Creator), University of York, 14 Jun 2018
DOI: 10.15124/65cd1dd8-c240-45a5-9a47-0ac6ff870f51, https://doi.org/10.1103/PhysRevB.97.235143