Increasing the applicability of density functional theory. III. Do consistent Kohn-Sham density functional methods...

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Current density functional theory (DFT) approximations often fail to provide accurate total energies and ionization potentials simultaneously.
• A
• consistent
• DFT requires that Kohn-Sham (KS) eigenvalues accurately approximate principal ionization potentials.

Purpose of the Study:

• To discuss the concept of a
• consistent
• KS-DFT.
• To introduce an ab initio DFT method based on the optimized effective potential (OEP) strategy as a solution.
• To explore the relationship between this ab initio DFT and other quantum chemical methods like MBPT2 and GW.

Main Methods:

• Utilizing the optimized effective potential (OEP) strategy for exchange and correlation within DFT.
• Representing the correlated density as a single determinant.
• Generating local exchange and correlation operators for self-consistent solutions of KS orbitals and eigenvalues.

Main Results:

• The ab initio DFT method with OEP satisfies the criteria for a
• consistent
• DFT.
• This method provides accurate approximations to principal ionization potentials.
• It offers a self-consistent, frequency-independent, effective independent particle alternative with a local correlation potential.

Conclusions:

• The ab initio DFT method based on OEP represents a significant step towards achieving a truly
• consistent
• DFT.
• This approach offers a computationally tractable alternative to methods involving frequency dependence, like the Dyson equation.
• It bridges the gap between traditional DFT and many-body perturbation theory (MBPT) and GW methods.