Description:

Wannier90 is a program for calculating maximally-localised Wannier functions
(MLWF) from a set of Bloch energy bands that may or may not be attached to or
mixed with other bands. The formalism works by minimising the total spread of
the MLWF in real space. This is done in the space of unitary matrices that
describe rotations of the Bloch bands at each k-point. As a result, wannier90
is independent of the basis set used in the underlying calculation to obtain
the Bloch states. Therefore, it may be interfaced straightforwardly to any
electronic structure code. The locality of MLWF can be exploited to compute
band-structure, density of states and Fermi surfaces at modest computational
cost.

Furthermore, wannier90 is able to output MLWF for visualisation and other
post-processing purposes. Wannier functions are already used in a wide variety
of applications. These include analysis of chemical bonding in real space;
calculation of dielectric properties via the modern theory of polarisation;
and as an accurate and minimal basis set in the construction of model
Hamiltonians for large-scale systems, in linear-scaling quantum Monte Carlo
calculations, and for efficient computation of material properties, such as
the anomalous Hall coefficient.