Incorporation of the Fermi-Amaldi Term into Direct Energy Kohn-Sham Calculations

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Direct energy Kohn-Sham (DEKS) theory approximates density functional theory electronic energy using orbital energies.
• The exchange-correlation potential in DEKS requires approximation, impacting accuracy.

Purpose of the Study:

• To incorporate the Fermi-Amaldi term into approximate DEKS calculations.
• To address the -1/r contribution in asymptotic regions and reduce self-interaction error.

Main Methods:

• Implementation of the Fermi-Amaldi term within the DEKS framework.
• Analysis of the exchange-correlation potential and electronic energies.

Main Results:

• The Fermi-Amaldi term introduces a necessary -1/r contribution to the potential.
• One-electron self-interaction error is effectively eliminated.
• Electronic energies show high sensitivity to methodology, while orbital energies and potentials remain robust.

Conclusions:

• The Fermi-Amaldi term offers a significant improvement for DEKS calculations.
• This approach enhances the accuracy and reliability of electronic structure predictions.