Constraining density functional approximations to yield self-interaction free potentials.

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Materials Science

Background:

• Self-interactions (SIs) are a significant issue in density functional approximations (DFAs).
• These errors cause substantial divergence from experimental data.
• Existing DFAs struggle with accurate asymptotic potential decay.

Purpose of the Study:

• To develop a method for optimizing density functional total energies.
• To eliminate self-interaction errors in the effective local potential.
• To ensure asymptotically correct potential behavior in DFAs.

Main Methods:

• Optimizing density functional total energies with respect to the effective local potential.
• Imposing constraints to ensure the effective potential is free from SI errors.
• Constraining the Hartree, exchange, and correlation potential to the electrostatic potential of a non-negative effective repulsive density of N-1 electrons.

Main Results:

• The proposed method effectively removes self-interaction errors.
• Optimal effective potentials exhibit correct asymptotic decay.
• Significant improvements in one-electron properties are achieved.

Conclusions:

• The constrained optimization approach successfully addresses SI errors in DFAs.
• This method leads to more accurate theoretical predictions.
• The approach offers a pathway to asymptotically correct and reliable density functional calculations.