Local scaling correction for reducing delocalization error in density functional approximations.

Area of Science:

• Quantum Chemistry
• Computational Materials Science

Background:

• Delocalization error is a fundamental issue in current density functional approximations.
• This error significantly impacts the accuracy of density functional theory (DFT) calculations for various chemical systems.

Purpose of the Study:

• To develop a universal scheme for alleviating delocalization error in DFT.
• To improve the accuracy of electronic structure calculations for challenging systems.

Main Methods:

• A local scaling correction scheme was developed.
• The Perdew-Parr-Levy-Balduz (PPLB) linearity condition was imposed on local system regions.
• The scheme was applied to mainstream density functional approximations.

Main Results:

• Substantial reduction in delocalization error was achieved.
• Significantly improved descriptions of dissociating molecules, transition-state species, and charge-transfer systems were obtained.
• The scheme demonstrated broad applicability across different DFT approximations.

Conclusions:

• Explicit treatment of fractional electron distributions is crucial for mitigating delocalization error.
• The developed local scaling correction scheme offers a promising approach for accurate DFT calculations.
• This work highlights the importance of addressing fundamental errors in electronic structure theory.