Electronic structure and dynamical correlations in antiferromagnetic BiFeO 3
Year: 2026
Type: article
Abstract: We study the electronic structure and dynamical correlations in antiferromagnetic BiFeO 3 , a prototypical room-temperature multiferroic, using a variety of static and dynamical first-principles methods. Conventional static Hubbard corrections ( DFT + U , DFT + U + V ) incorrectly predict a deep-valence Fe 3 d peak (around − 7 eV ) in antiferromagnetic BiFeO 3 , in contradiction with hard x-ray photoemission. We resolve this failure by using a recent generalization of DFT + U to include a frequency-dependent screening— DFT + U ( ω ) —or using a dynamical Hubbard functional. The screened Coulomb interaction U ( ω ) , computed with spin-polarized random-phase approximation and projected onto maximally localized Fe 3 d Wannier orbitals, is expressed as a sum over poles, yielding a self-energy that augments the Kohn-Sham Hamiltonian. This DFT + U ( ω ) approach predicts a fundamental band gap of 1.53 eV , consistent with experiments, and completely eliminates the unphysical deep-valence peak. The resulting simulated hard x-ray photoelectron spectroscopy spectrum reproduces the experimental line shape with an accuracy comparable to state-of-the-art approaches. Our work highlights the critical nature of dynamical screening in complex oxides and of DFT + U ( ω ) as a predictive and computationally efficient approach to address the electronic structure of correlated materials.
Source: Physical Review Research
DOI: 10.1103/stw8-9mld
Authors: Yihan Wu, Mario Caserta, Tommaso Chiarotti, Nicola Marzari
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,625
OpenAlex ID: W7108221479