Accurate total energies from the adiabatic-connection fluctuation-dissipation theorem

TY - JOUR

T1 - Accurate total energies from the adiabatic-connection fluctuation-dissipation theorem

AU - Woods, N. D.

AU - Entwistle, M. T.

AU - Godby, R. W.

N1 - Funding Information: The authors thank Micheal Hutcheon for helpful discussions. N.D.W. is supported by the EPSRC Centre for Doctoral Training in Computational Methods for Materials Science for funding under Grant No. EP/L015552/1. We are grateful for computational support from the UK national high performance computing service, ARCHER, through the UKCP consortium under EPSRC Grant No. EP/P022596/1. © 2021 American Physical Society. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details

PY - 2021/9/17

Y1 - 2021/9/17

N2 - In the context of inhomogeneous one-dimensional finite systems, recent numerical advances [Phys. Rev. B 103, 125155 (2021)2469-995010.1103/PhysRevB.103.125155] allow us to compute the exact coupling-constant dependent exchange-correlation kernel fxcλ(x,x′,ω) within linear response time-dependent density-functional theory. This permits an improved understanding of ground-state total energies derived from the adiabatic-connection fluctuation-dissipation theorem (ACFDT). We consider both one-shot and self-consistent ACFDT calculations, and demonstrate that chemical accuracy is reliably preserved when the frequency dependence in the exact functional fxc[n](ω=0) is neglected. This performance is understood on the grounds that the exact fxc[n] varies slowly over the most relevant ω range (but not in general), and hence the spatial structure in fxc[n](ω=0) is able to largely remedy the principal issue in the present context: self-interaction (examined from the perspective of the exchange-correlation hole). Moreover, we find that the implicit orbitals contained within a self-consistent ACFDT calculation utilizing the adiabatic exact kernel fxc[n](ω=0) are remarkably similar to the exact Kohn-Sham orbitals, thus further establishing that the majority of the physics required to capture the ground-state total energy resides in the spatial dependence of fxc[n] at ω=0.

AB - In the context of inhomogeneous one-dimensional finite systems, recent numerical advances [Phys. Rev. B 103, 125155 (2021)2469-995010.1103/PhysRevB.103.125155] allow us to compute the exact coupling-constant dependent exchange-correlation kernel fxcλ(x,x′,ω) within linear response time-dependent density-functional theory. This permits an improved understanding of ground-state total energies derived from the adiabatic-connection fluctuation-dissipation theorem (ACFDT). We consider both one-shot and self-consistent ACFDT calculations, and demonstrate that chemical accuracy is reliably preserved when the frequency dependence in the exact functional fxc[n](ω=0) is neglected. This performance is understood on the grounds that the exact fxc[n] varies slowly over the most relevant ω range (but not in general), and hence the spatial structure in fxc[n](ω=0) is able to largely remedy the principal issue in the present context: self-interaction (examined from the perspective of the exchange-correlation hole). Moreover, we find that the implicit orbitals contained within a self-consistent ACFDT calculation utilizing the adiabatic exact kernel fxc[n](ω=0) are remarkably similar to the exact Kohn-Sham orbitals, thus further establishing that the majority of the physics required to capture the ground-state total energy resides in the spatial dependence of fxc[n] at ω=0.

UR - http://www.scopus.com/inward/record.url?scp=85115812541&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.104.125126

DO - 10.1103/PhysRevB.104.125126

M3 - Article

AN - SCOPUS:85115812541

SN - 2469-9950

VL - 104

JO - Physical Review B

JF - Physical Review B

IS - 12

M1 - 125126

ER -