All-electron quasiparticle self-consistent GW for molecules and periodic systems within the numerical atomic orbital...

Area of Science:

• Computational Chemistry
• Condensed Matter Physics
• Materials Science

Background:

• The GW approximation is crucial for accurate electronic structure calculations.
• Existing methods often face limitations in scalability and computational cost for large systems.
• Numerical Atomic Orbitals (NAOs) offer a promising avenue for developing efficient electronic structure algorithms.

Purpose of the Study:

• To implement an all-electron quasiparticle self-consistent GW (QSGW) method using Numerical Atomic Orbitals (NAOs).
• To enable accurate and efficient electronic structure calculations for both molecular and periodic systems.
• To pave the way for large-scale QSGW computations.

Main Methods:

• Developed an all-electron QSGW implementation within the LibRPA software package.
• Utilized the space-time formalism combined with the localized resolution-of-identity approximation.
• Employed analytical continuation of the self-energy matrix with the "Mode B" QSGW scheme for stable spectra.

Main Results:

• Achieved stable self-consistent quasiparticle energy spectra.
• Demonstrated accurate calculation of molecular ionization potentials.
• Obtained reliable quasiparticle bandgaps for semiconductors and insulators, consistent with established methods.

Conclusions:

• The NAO-based QSGW implementation provides accurate electronic properties for diverse systems.
• This method significantly enhances the feasibility of large-scale QSGW calculations.
• Leverages a previously developed low-scaling algorithm for G0W0 calculations, extending its applicability.