Constrained-Orbital Density Functional Theory. Computational Method and Applications to Surface Chemical Processes.

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Materials Science

Background:

• Density-functional theory (DFT) struggles with transparency in large calculations and describing systems with localized electrons or static correlation.
• Semilocal DFT approximations have limitations in accurately modeling complex electronic structures.

Purpose of the Study:

• To present a novel constrained-orbital DFT (CO-DFT) method.
• To address shortcomings in standard DFT regarding electronic structure transparency and the description of localized electrons.
• To enhance the study of chemical processes and static correlation.

Main Methods:

• Implementing a method where Kohn-Sham orbitals are constrained to atomic localizations within DFT.
• Utilizing CO-DFT to decompose complex orbital transformations into simpler, intuitive steps.
• Applying CO-DFT to generate configuration states for multiconfiguration Kohn-Sham calculations.

Main Results:

• CO-DFT enhances transparency in large-scale DFT calculations by simplifying orbital transformations.
• The method improves the description of systems with localized electrons and static correlation.
• Demonstrated applications in elementary steps of the oxygen evolution reaction.

Conclusions:

• CO-DFT offers a powerful approach to overcome limitations in standard DFT.
• The method provides more interpretable electronic structure insights for complex chemical systems.
• CO-DFT is valuable for studying reactions involving localized electrons and static correlation, such as in the oxygen evolution reaction.