Towards a First-Principles Determination of Effective Coulomb Interactions in Correlated Electron Materials: Role of Intershell Interactions

• Published in: Physical review letters Vol. 119; no. 5; p. 056401
• Main Authors: Seth, Priyanka, Hansmann, Philipp, van Roekeghem, Ambroise, Vaugier, Loig, Biermann, Silke
• Format: Journal Article
• Language: English
• Published: United States 04.08.2017
• ISSN: 1079-7114
• DOI: 10.1103/PhysRevLett.119.056401

The determination of the effective Coulomb interactions to be used in low-energy Hamiltonians for materials with strong electronic correlations remains one of the bottlenecks for parameter-free electronic structure calculations. We propose and benchmark a scheme for determining the effective local Coulomb interactions for charge-transfer oxides and related compounds. Intershell interactions between electrons in the correlated shell and ligand orbitals are taken into account in an effective manner, leading to a reduction of the effective local interactions on the correlated shell. Our scheme resolves inconsistencies in the determination of effective interactions as obtained by standard methods for a wide range of materials, and allows for a conceptual understanding of the relation of cluster model and dynamical mean field-based electronic structure calculations.