Charge self-consistent many-body corrections using optimized projected localized orbitals.

Area of Science:

• Computational materials science
• Condensed matter physics
• Quantum chemistry

Background:

• Combining ab initio density-functional theory (DFT) with many-body techniques is essential for accurate material simulations.
• Existing implementations often lack flexibility, speed, and ease of use, hindering routine application.
• Projector augmented wave (PAW) methods are widely used in electronic structure calculations.

Purpose of the Study:

• To present a flexible, fast, and user-friendly implementation of a general charge self-consistent scheme.
• To integrate this scheme within the projector augmented wave (PAW) framework using the Vienna Ab Initio Simulation Package (VASP).
• To benchmark the implementation using dynamical mean-field theory (DMFT) on NiO and SrVO3.

Main Methods:

• Developed a charge self-consistent scheme using projected localized orbitals within the PAW framework.
• Optimized projector selection and total energy calculation procedures.
• Applied the implementation with Hartree-Fock (HF) for NiO and continuous-time quantum Monte Carlo (CT-QMC) for SrVO3.

Main Results:

• Charge self-consistency reduces the dependence of the spectral function and band gap on the double-counting correction in NiO.
• Optimized projectors offer advantages over non-optimized ones.
• Electronic correlations significantly influence the structure of monolayer SrVO3, affecting apical oxygen positions and layer thickness.

Conclusions:

• The presented implementation enhances the routine application of combined DFT and many-body methods.
• Charge self-consistency is crucial for accurate spectral properties, particularly band gaps.
• Accurate structural determination requires considering electronic correlations in low-dimensional materials.