Wannier Functions

Overview

This skill group covers the construction of maximally localized Wannier functions (MLWFs) from DFT Bloch states. Wannier functions provide a real-space, localized representation of electronic structure that enables tight-binding model construction, Wannier-interpolated band structures, topological invariant calculations, and electron-phonon coupling.

Sub-Skills

Method Decision Guide

Need Wannier functions or tight-binding Hamiltonian?
  YES --> wannier90-workflow/
  Need topological invariants (Z2, Chern number)?
    YES --> wannier90-workflow/ (then use WannierTools or custom Z2 script)
  Need Wannier-interpolated band structure?
    YES --> wannier90-workflow/ (produces smooth interpolated bands on arbitrary k-paths)
  Need electron-phonon coupling via Wannier interpolation?
    YES --> wannier90-workflow/ (provides the Wannier basis for EPW)

Common Prerequisites

• Quantum ESPRESSO: pw.x for SCF/NSCF, pw2wannier90.x for interface.
• Wannier90: wannier90.x binary or Python interface. If the binary is not available, the workflow explains alternatives.
• Pseudopotentials: SSSP or PSlibrary UPF files (see electronic-structure/scf-relax skill).
• Python packages: pymatgen, numpy, matplotlib for post-processing.