Z2Pack automates the calculation of topological numbers of band-structures. If works with both first-principles calculations (z2pack.fp) and tight-binding models (z2pack.tb).

The topological numbers are computed from the evolution of Wannier charge centers (WCC), as described in this paper for the case of the Z2 invariant.

The WCC are calculated from overlap matrices which are calculated either directly (for tb) or via the Wannier90 code package (fp).

• Documentation: http://z2pack.ethz.ch/doc
• Online interface: http://z2pack.ethz.ch/online