A new constraint DFT technique for self-consistent determination of U values.

Area of Science:

• Computational Materials Science
• Condensed Matter Physics
• Quantum Chemistry

Background:

• Accurately describing strongly correlated electronic systems (SCESs) is crucial for understanding material properties.
• Existing methods often rely on empirical parameters, limiting predictive power.
• The effective on-site-interaction parameter (Ueff) is key to modeling electron correlation effects.

Purpose of the Study:

• To develop a novel, parameter-free computational technique for calculating Ueff within density functional theory (DFT).
• To integrate this technique with projector augmented wave (PAW) and pseudopotential (PP) methods.
• To enable self-consistent DFT+U calculations for SCESs.

Main Methods:

• Developed a constraint density functional theory (DFT) technique.
• Integrated the technique with projector augmented wave (PAW) and pseudopotential (PP) methods.
• Employed the DFT+U framework for self-consistent Ueff calculations.

Main Results:

• Successfully determined the Ueff for correlated electrons in neodymium sesquioxide (Nd2O3) and iron oxide (FeO).
• Demonstrated the effectiveness of the developed technique for SCESs.
• Achieved first-principles DFT+U PAW and PP calculations free from empirical parameters.

Conclusions:

• The new constraint DFT technique provides a physically meaningful Ueff, directly influencing electronic structure.
• This parameter-free approach enhances the accuracy and reliability of computational studies on SCESs.
• The method is applicable to various materials, including Nd2O3 and FeO, using established computational frameworks.