Quasiparticle Self-Consistent GW Study of Simple Metals.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Quantum Chemistry

Background:

• The GW method is a standard for calculating electronic band structures from first principles.
• Its application to metallic systems, especially self-consistently, is less common than for semiconductors and insulators.
• Recent debates challenge the established view of simple metals as nearly free electron gases.

Purpose of the Study:

• To investigate all-electron quasiparticle self-consistent GW (QSGW) calculations for simple metals.
• To compare QSGW results with single-shot G0W0, DFT-LDA, and experimental photoemission data.
• To assess the role of self-consistency in GW calculations for metallic systems.

Main Methods:

• All-electron quasiparticle self-consistent GW (QSGW) calculations.
• Full-potential linearized augmented-plane-wave (FP-LAPW) approach.
• Comparison with single-shot G0W0, density-functional theory (DFT) in the local-density approximation (LDA), and experimental measurements.

Main Results:

• DFT-LDA calculations tend to overestimate material bandwidths.
• GW quasiparticle renormalization corrects bandwidths but requires self-consistency for accurate agreement with photoemission data.
• Simple metals behave as nearly free electron gases with weak electronic correlation, confirming existing beliefs.

Conclusions:

• Fully self-consistent QSGW calculations are crucial for accurately determining the electronic band structure of simple metals.
• The findings support the long-held view of simple metals as weakly correlated systems.
• This work provides important validation in the context of recent challenges to this established understanding.