  Systematic and automatic calculations of the electronic band structure are a
crucial component of computationally-driven high-throughput materials
screening. An algorithm, for any crystal, to derive a unique description of the
crystal structure together with a recommended band path is indispensable for
this task. The electronic band structure is typically sampled along a path
within the first Brillouin zone including the surface in reciprocal space. Some
points in reciprocal space have higher site symmetries and/or have higher
constraints than other points regarding the electronic band structure and
therefore are likely to be more important than other points. This work
categorizes points in reciprocal space according to their symmetry and provides
recommended band paths that cover all special wavevector (k-vector) points and
lines necessarily and sufficiently. Points in reciprocal space are labeled such
that there is no conflict with the crystallographic convention. The k-vector
coefficients of labeled points, which are located at Brillouin zone face and
edge centers as well as vertices, are derived based on a primitive cell
compatible with the crystallographic convention, including those with axial
ratio-dependent coordinates. Furthermore, we provide an open-source
implementation of the algorithms within our SeeK-path python code, to allow
researchers to obtain k-vector coefficients and recommended band paths in an
automated fashion. Finally, we created a free online service to compute and
visualise Brillouin Zone, labeled k-points and suggested band paths for any
crystal structure, that we made available at
http://www.materialscloud.org/tools/seekpath/ .
