Multiplet ligand-field theory using Wannier orbitals

• Verfasst von: Haverkort, Maurits W. [VerfasserIn]
• Verfasst von: Zwierzycki, Maciej [VerfasserIn]
• Verfasst von: Andersen, Ole Krogh [VerfasserIn]
• Titel: Multiplet ligand-field theory using Wannier orbitals
• Verf.angabe: M.W. Haverkort, M. Zwierzycki, and O.K. Andersen
• E-Jahr: 2012
• Jahr: 9 April 2012
• Umfang: 20 S.
• Teil: volume:85
• Teil: year:2012
• Teil: number:16
• Teil: pages:165113
• Teil: extent:20
• Fussnoten: Gesehen am 06.10.2017
• Titel Quelle: Enthalten in: Physical review / B
• Ort Quelle: College Park, Md. : APS, 1970
• Jahr Quelle: 2012
• Band/Heft Quelle: 85(2012,16) Artikel-Nummer 165113, 20 Seiten
• ISSN Quelle: 1550-235X
• DOI: doi:10.1103/PhysRevB.85.165113
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1564141012

Abstract

We demonstrate how ab initio cluster calculations including the full Coulomb vertex can be done in the basis of the localized Wannier orbitals which describe the low-energy density functional (local-density approximation) band structure of an infinite crystal, e.g., the transition-metal 3d and oxygen 2p orbitals. The spatial extent of our 3d Wannier orbitals (orthonormalized Nth-order muffin-tin orbitals) is close to that found for atomic Hartree-Fock orbitals. We define ligand orbitals as those linear combinations of the O 2p Wannier orbitals which couple to the 3d orbitals for the chosen cluster. The use of ligand orbitals allows for a minimal Hilbert space in multiplet ligand-field theory calculations, thus reducing the computational costs substantially. The result is a fast and simple ab initio theory, which can provide useful information about local properties of correlated insulators. We compare results for NiO, MnO, and SrTiO3 with x-ray absorption, inelastic x-ray scattering, and photoemission experiments. The multiplet ligand-field theory parameters found by our ab initio method agree within ∼10% with known experimental values.