band-structure interpolator and transport coefficient calculator
BoltzTraP2 provides a numerically stable and efficient method for obtaining analytic representations of electronic bands based on density-functional-theory results for relatively sparse grids. It achieves this goal by using smoothed Fourier interpolation.
BoltzTraP2 can be used as a Python module or as a standalone command-line program. One of its most frequent use cases involves determining the Onsager electronic transport coefficients by direct integration over the Brillouin zone based on the interpolated band structure, as functions of temperature and chemical potential. This functionality is easy to access in BoltzTraP,2 which also includes many additional features for band-structure analysis, such as a 3D viewer of the Fermi surface.
The program and the method are described in detail in the following reference: G. Madsen, J. Carrete & M. J. Verstraete, Comput. Phys. Commun.