Selfconsistent random phase approximation methods

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Density functional theory (DFT) is a powerful tool for electronic structure calculations.
• Random Phase Approximation (RPA) offers a way to calculate correlation energies.
• Achieving self-consistency in RPA calculations within DFT remains a challenge.

Purpose of the Study:

• To review recent advancements in self-consistent calculations of ground-state energies using RPA within DFT.
• To introduce and evaluate the generalized Kohn-Sham semicanonical projected RPA (GKS-spRPA) method.
• To highlight the importance of functional self-consistency (FSC) for accurate electronic structure calculations.

Main Methods:

• Review of existing self-consistent RPA schemes and their limitations regarding FSC.
• Detailed examination of the GKS-spRPA method and its approach to satisfying FSC.
• Comparative analysis of GKS-spRPA against non-selfconsistent RPA, OEP-RPA, GW, and orbital optimization methods.

Main Results:

• Existing self-consistent RPA schemes generally violate FSC.
• GKS-spRPA demonstrates significant improvements in densities, binding energies, and molecular properties.
• GKS-spRPA accurately predicts ionization potentials and electron affinities.

Conclusions:

• Functional self-consistency (FSC) is crucial for accurate density functional calculations, especially for explicitly potential-dependent functionals.
• GKS-spRPA represents a substantial step towards satisfying FSC in RPA calculations.
• The findings suggest that the Kohn-Sham potential should be defined via FSC for improved accuracy.