Comparison of local density functionals based on electron gas and finite systems

TY - JOUR

T1 - Comparison of local density functionals based on electron gas and finite systems

AU - Entwistle, M. T.

AU - Casula, Michele

AU - Godby, R. W.

N1 - ©2018 American Physical Society

PY - 2018/6/25

Y1 - 2018/6/25

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=85049195521&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.97.235143

DO - 10.1103/PhysRevB.97.235143

M3 - Article

AN - SCOPUS:85049195521

SN - 2469-9950

VL - 97

SP - 1

EP - 8

JO - Physical Review B

JF - Physical Review B

IS - 23

M1 - 235143

ER -