Orbital-Resolved DFT+U for Molecules and Solids

Area of Science:

• Computational Chemistry
• Condensed Matter Physics
• Quantum Chemistry

Background:

• Density-functional theory (DFT) with Hubbard U correction (DFT+U) is widely used for materials science.
• Conventional DFT+U often uses a shell-averaged approach, limiting accuracy for complex electronic structures.
• Accurate modeling of localized and hybridized electronic states remains a challenge.

Purpose of the Study:

• To introduce an orbital-resolved extension of the Hubbard U correction to DFT.
• To enhance the prediction accuracy of energetic, electronic, and structural properties.
• To provide a computationally efficient and accurate tool for electronic structure calculations.

Main Methods:

• Developed an orbital-resolved extension of the Hubbard U correction.
• Obtained numerical Hubbard parameters using linear-response calculations.
• Applied the method to bulk solids (FeS2, beta-MnO2) and Fe(II) molecular complexes.

Main Results:

• The orbital-resolved approach significantly improves property predictions compared to shell-averaged methods.
• Accuracy is particularly enhanced for compounds with both localized and hybridized states.
• Demonstrated applicability to diverse systems including solids and molecular complexes.

Conclusions:

• A careful definition of Hubbard manifolds is crucial for extending DFT+U.
• The orbital-resolved scheme offers a computationally accessible yet accurate method.
• This approach is valuable for charge-transfer insulators, transition-metal complexes, and hybridized systems.