(Spin-)density-functional theory for open-shell systems: Exact magnetization density functional for the half-filled Hubbard trimer
Year: 2019
Type: article
Abstract: According to the Hohenberg-Kohn theorem of density-functional theory (DFT), all observable quantities of systems of interacting electrons can be expressed as functionals of the ground-state density. This includes, in principle, the spin polarization (magnetization) of open-shell systems; the explicit form of the magnetization as a functional of the total density is however unknown. In practice, open-shell systems are always treated with spin-DFT, where the basic variables are the spin densities. Here the relation between DFT and spin-DFT for open-shell systems is illustrated and the exact magnetization density functional is obtained for the half-filled Hubbard trimer. Errors arising from spin-restricted and -unrestricted exact-exchange Kohn-Sham calculations are analyzed and partially resolved via the exact magnetization functional.
Source: Physical Review A
Author: Carsten A. Ullrich
Institution: University of Missouri
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2945689294