Optimized effective potential method and application to static RPA correlation.

Area of Science:

• Computational Physics
• Quantum Chemistry
• Materials Science

Background:

• The optimized effective potential (OEP) method offers a pathway to accurate ground-state properties in density functional theory.
• High computational cost and theoretical ambiguities limit the widespread adoption of OEP methods.
• Accurate calculation of electronic structure and magnetic properties is crucial for materials development.

Purpose of the Study:

• To address the computational expense and theoretical ambiguities associated with the OEP method.
• To develop an accelerated OEP scheme applicable to advanced correlation functionals.
• To improve the description of magnetic transition metals using OEP.

Main Methods:

• An accelerated OEP scheme was developed using a static random phase approximation (RPA)-level correlation functional.
• The Krieger-Li-Iafrate (KLI) approximation was employed to solve the OEP equation efficiently.
• The OEP method was reformulated for direct RPA and other precise correlation functionals, incorporating Fermi surface level-crossing and Kohn-Sham eigenvalue variations.

Main Results:

• The accelerated OEP method significantly reduces computational cost.
• The KLI approximation maintained high accuracy for the magnetic properties of iron, cobalt, and nickel.
• The reformulated OEP method provides a distinct and potentially more accurate OEP equation.

Conclusions:

• The developed methods overcome key limitations of the OEP approach, making it more practical.
• The study demonstrates the viability of OEP for accurate magnetic property predictions in transition metals.
• This work paves the way for broader application of advanced OEP methods in electronic structure calculations.