Work

DFT + U + V is equivalent to DFT + U with density-dependent hybridized projectors

Year: 2026

Type: article

Abstract: Hubbard-corrected density-functional theory ( DFT + U ) is a popular tool for first-principles modeling of materials with localized d or f electrons, but its on-site corrections tend to over-localize charge and break covalent bonds. Intersite + V corrections were introduced to counter this and are now widely used, but a formal justification has been lacking. Here, we show that—to first order in V / U —intersite corrections are exactly equivalent to on-site DFT + U evaluated on a density-matrix-dependent redefinition of the Hubbard projectors, hybridized with those of neighboring sites, providing insight into the explicit mechanism by which V affects covalency. If the projectors are held frozen, as is common practice, the equivalence partially breaks down. Beyond reinterpreting the formalism, these results sharpen the questions of how V should be computed and what the Hubbard subspaces fundamentally are.

Source: Physical Review Research

DOI: 10.1103/qghb-78nd

Authors: Edward Linscott, Alberto Carta, Nicola Marzari

Institutions: Paul Scherrer Institute, University of Cambridge, École Polytechnique Fédérale de Lausanne

Language: English

Topic: Advanced Chemical Physics Studies

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,625

Funders: National Science Foundation, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, National Center of Competence in Research Materials’ Revolution: Computational Design and Discovery of Novel Materials