WannSymm: A symmetry analysis code for Wannier orbitals

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. Program summaryProgram Title: WannSymmCPC Library link to program files:https://doi.org/10.17632/zgf4p85pwx.1Licensing provisions: BSD 3-clauseProgramming language: CExternal libraries: spglib; BLAS and LAPACK; MPI libraries (optional)Nature of problem: Generate the symmetry operators in Wannier basis; calculate the symmetry eigenvalues and characters; symmetrize the real-space Hamiltonian according to the crystal structure. It deals with nonmagnetic or magnetic systems with or without spin-orbit coupling. For magnetic systems, it can deal with ferromagnetic, commensurate antiferromagnetic long range ordered collinear or non-collinear systems with spin-orbit coupling.Solution method: The code requires the real-space Hamiltonian from Wannier projection, the definition of Wannier basis and the crystal structure associated with the defined basis.