# Wannier90

GPL Wannier90 development team Github

Wannier90 is a code for computing the maximally-localized Wannier functions (MLWFs) of a system. It requires a separate electronic structure code to compute and provide information on the Kohn-Sham energy bands. It can operate either as a standalone post-processing utility, reading this information from files, or as a library to be called internally by the electronic structure code.

Wannier90 has a number of features, including a disentanglement scheme for entangled energy bands, optimized Γ-point routines, plotting of the MLWFs, Wannier interpolation to obtain many spectral and Fermi-surface properties at high-resolution in the Brillouin zone, and others. A complete list of features is maintained here.

## Algorithm

Wannier90 computes MLWFs following the method of Marzari and Vanderbilt1 (MV). For entangled energy bands, the method of Souza, Marzari, and Vanderbilt2 (SMV) is used. The implementation of these methods for Wannier90 is described here3, and in the user guide (Chapter 1).

## Programming interface

The interface for using Wannier90 as a library is described in the user guide (Chapter 6).

## Installation

### Prerequisites

• Fortran 95 compiler
• BLAS + LAPACK
• MPI (optional for parallel execution of some post-processing utilities)

### Instructions

The system dependent parameters (e.g. compiler name) are contained in a file called make.sys. Sample files may be found in the ./config/ directory. Choose one that is nearest to your setup and copy it to make.sys. You may need to edit it, for example to give the correct library path for your machine.

On a Linux system with the Intel compiler, build Wannier90 by typing:

cp ./config/make.sys.ifort ./make.sys
make


For more detailed installation instructions, see the README.install file in the source code.

### Tests

To run the test cases, type:

make test


## References

1. N. Marzari and D. Vanderbilt, Maximally localized generalized Wannier functions for composite energy bands, Phys. Rev. B 56, 12847 (1997). DOI: 10.1103/PhysRevB.56.12847 ↩︎

2. I. Souza, N. Marzari, and D. Vanderbilt, Maximally localized Wannier functions for entangled energy bands, Phys. Rev. B 65, 035109 (2001). DOI: 10.1103/PhysRevB.65.035109 ↩︎

3. A. A. Mostofi, J. R. Yates, Y.-S. Lee, I. Souza, D. Vanderbilt, and N. Marzari, wannier90: A Tool for Obtaining Maximally-Localised Wannier Functions, Comput. Phys. Commun. 178, 685 (2008). DOI: 10.1016/j.cpc.2007.11.016 ↩︎