Berry: A code for the differentiation of Bloch wavefunctions from DFT calculations

TL;DR

Berry is a software suite that enhances DFT calculations by enabling the differentiation of Bloch wavefunctions, allowing the computation of Berry-related properties in two-dimensional materials like hBN and InSe.

Contribution

The paper introduces Berry, a software tool that extends DFT calculations to compute Berry connections and curvatures for 2D materials, facilitating advanced electronic property analysis.

Findings

Successfully implemented for 2D materials like hBN and InSe

Enables calculation of Berry connections and curvatures

Enhances the analysis of electronic structures in DFT

Abstract

Density functional calculations of electronic structures of materials is one of the most used techniques in theoretical solid state physics. These calculations retrieve single electron wavefunctions and their eigenenergies. The berry suite of programs amplifies the usefulness of DFT by ordering the eigenstates in analytic bands, allowing the differentiation of the wavefunctions in reciprocal space. It can then calculate Berry connections and curvatures and the second harmonic generation conductivity. The berry software is implemented for two dimensional materials and was tested in hBN and InSe. In the near future, more properties and functionalities are expected to be added.