WannSymm: A symmetry analysis code for Wannier orbitals

TL;DR

WannSymm is a software tool that applies symmetry analysis to Wannier orbitals, improving the accuracy of Hamiltonians and enabling detailed symmetry-based studies of electronic structures.

Contribution

The paper introduces explicit symmetry operator expressions for Wannier basis and implements them in WannSymm, enhancing symmetry analysis capabilities for Wannier-based calculations.

Findings

Symmetrized Hamiltonians improve nodal structure searches.

WannSymm accurately generates symmetry operators at specific k-points.

The software enhances symmetry analysis in Wannier band structures.

Abstract

We derived explicit expressions of symmetry operators on Wannier basis, and implemented these operators in WannSymm software. Based on this implementation, WannSymm can i) symmetrize the real-space Hamiltonian output from Wannier90 code, ii) generate symmetry operators of the little group at a specific k-point, and iii) perform symmetry analysis for Wannier band structure. In general, symmetrized Hamiltonians yield improved results compared with the original ones when they are employed for nodal structure searching, surface Green's function calculations, and other model calculations.