Correlation-induced corrections to the band structure of boron nitride: a wave-function-based approach

TL;DR

This paper presents a wave-function-based ab initio method to accurately compute correlation-induced corrections to the electronic band structure of zinc-blende boron nitride, emphasizing local charge effects and polarization.

Contribution

It introduces a systematic wave-function-based local Hamiltonian approach for calculating correlation effects on the band structure of BN, including local charge redistribution and long-range polarization.

Findings

On-site and nearest-neighbor charge relaxation corrections of several eV to the band gap.

Long-range polarization effects further modify the band gap.

Final calculated gap agrees well with experimental data.

Abstract

We present a systematic study of the correlation-induced corrections to the electronic band structure of zinc-blende BN. Our investigation employs an ab initio wave-function-based local Hamiltonian formalism which offers a rigorous approach to the calculation of the polarization and local charge redistribution effects around an extra electron or hole placed into the conduction or valence bands of semiconducting and insulating materials. Moreover, electron correlations beyond relaxation and polarization can be readily incorporated. The electron correlation treatment is performed on finite clusters. In conducting our study, we make use of localized Wannier functions and embedding potentials derived explicitly from prior periodic Hartree-Fock calculations. The on-site and nearest-neighbor charge relaxation bring corrections of several eV to the Hartree-Fock band gap. Additional corrections are caused by long-range polarization effects. In contrast, the dispersion of the Hartree-Fock bands is marginally affected by electron correlations. Our final result for the fundamental gap of zinc-blende BN compares well with that derived from soft x-ray experiments at the B and N K-edges.