Simple iterative construction of the optimized effective potential for orbital functionals, including exact exchange.

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Orbital-dependent functionals in electronic structure theory require solving the optimized effective potential (OEP) integral equation.
• The traditional OEP solution is computationally demanding, limiting the application of these functionals.
• Accurate calculation of exchange-correlation potentials is crucial for predicting material properties.

Purpose of the Study:

• To develop a more efficient and accessible method for calculating the optimized effective potential (OEP).
• To overcome the computational bottlenecks associated with solving the OEP integral equation.
• To enable wider application of orbital-dependent functionals in electronic structure calculations.

Main Methods:

• An iterative approach is proposed to solve the OEP, utilizing partial differential equations for orbital shifts.
• The Krieger-Li-Iafrate (KLI) approximation is employed to simplify the OEP solution.
• The method avoids the explicit calculation of unoccupied Kohn-Sham orbitals.

Main Results:

• The iterative OEP method demonstrates accuracy and efficiency for atomic and cluster systems.
• Exact-exchange energy calculations confirm the validity of the proposed approach.
• The study reveals counterintuitive asymptotic limits of the exact OEP.

Conclusions:

• The developed iterative OEP method offers a computationally feasible alternative to traditional approaches.
• This advancement facilitates the use of orbital-dependent functionals in quantum chemistry and materials science.
• The findings contribute to more accurate and efficient electronic structure calculations.