Generalized Kohn-Sham equations with accurate total energy and single-particle eigenvalue spectrum

Area of Science:

• Quantum Chemistry
• Computational Materials Science
• Electronic Structure Theory

Background:

• Accurate prediction of electronic structure is crucial for understanding material properties.
• Existing methods like Kohn-Sham theory face challenges with self-interaction errors.
• Improving the accuracy of single-particle eigenvalue spectra is an ongoing research goal.

Purpose of the Study:

• To develop a generalized Kohn-Sham or constrained hybrid method.
• To improve the accuracy of single-particle eigenvalue spectra.
• To minimize the increase in total energy while enhancing spectral accuracy.

Main Methods:

• A new generalized Kohn-Sham or constrained hybrid method is proposed.
• The exchange potential is an average of nonlocal Fock-exchange and self-interaction-corrected exchange potentials.
• A constrained minimization method of semi-local approximations is employed.

Main Results:

• The new method yields an accurate single-particle eigenvalue spectrum.
• Average deviation for valence orbital eigenvalues and experimental ionization potentials is approximately 0.5 eV.
• Deviation for core orbitals is within 2 eV.
• These improvements are achieved with a minimal increase in total energy.

Conclusions:

• The proposed hybrid method offers a significant improvement in predicting electronic structure.
• It provides accurate ionization potentials and eigenvalue spectra.
• The method balances accuracy with computational cost effectively.