Density functional versus spin-density.pdf (914.32 kB)

Density functional versus spin-density functional and the choice of correlated subspace in multivariable effective action theories of electronic structure

Download (914.32 kB)
journal contribution
posted on 05.11.2015 by H. Park, AJ Millis, CA Marianetti
Modern extensions of density functional theory such as the density functional theory plus U and the density functional theory plus dynamical mean field theory require choices, including selection of variable (charge vs spin density) for the density functional and specification of the correlated subspace. This paper examines these issues in the context of the “plus U” extensions of density functional theory, in which additional correlations on specified correlated orbitals are treated using a Hartree-Fock approximation. Differences between using charge-only or spin-density-dependent exchange-correlation functionals and between Wannier and projector-based definitions of the correlated orbitals are considered on the formal level and in the context of the structural energetics of the rare-earth nickelates. It is demonstrated that theories based on spin-dependent exchange-correlation functionals can lead to large and in some cases unphysical effective on-site exchange couplings. Wannier and projector-based definitions of the correlated orbitals lead to similar behavior near ambient pressure, but substantial differences are observed at large pressures. Implications for other beyond density functional methods such as the combination of density functional and dynamical mean field theory are discussed.

Categories

Keyword(s)

Funding

A.J.M. acknowledges support from the Basic Energy Sciences Division of the US Department of Energy under Grant No. ER-046169. H.P. and C.A.M. acknowledge support from FAME, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the US Department of Energy under Contract No. DE-AC02- 05CH11231.

History

Publisher Statement

This is the copy of an article published in Physical Review B © 2015 American Physical Society Publications

Publisher

American Physical Society

issn

1098-0121

Issue date

27/07/2015

Exports

Categories

Keyword(s)

Exports