libNEGF

libNEGF is a general library for Non Equilibrium Green’s Functions.

With libNEGF you can calculate Equilibrium and Non Equilibrium Green’s Function in open systems and related quantities, within an efficient sparse iterative scheme.

libNEGF is available under LGPL license.

Have a look at the contributor’s guide if you want to help developing libNEGF.

For an example of application, see the use of libNEGF in DFTB+.

If you used libNEGF, please cite the following publication:

A. Pecchia, L. Salvucci, G. Penazzi and A. Di Carlo: "Non-equilibrium Green's functions in density functional tight binding: method and applications". New Journal of Physics 10, 065022 (2008). DOI: 10.1088/1367-2630/10/6/065022.

Installation

libNEGF requires

• CMake,

• a C99 compiler,

• a Fortran 2018 compiler,

• BLAS,

• LAPACK, and

• MPI 3.

Optionally CUDA can be used.

Note that MPICH version 4 may cause build problems due to the mpifx dependency, see mpifx#48. Moreover it is recommended to use recent gfortran releases: gfortran 11 and 12 are known to work, gfortran 10.2.1 (found in Debian 11) and GCC 8.3.0 (found in Debian 10) are known not to work.

Generating libNEGF Input

To create libNEGF input, obtain Slater-Koster parameterizations^[1] for the molecule at hand (e.g., from the DFTB+ Parameters page) and describe the geometric properties of the molecule and its contacts. The description file format as well as visualization of input and output are described in details in the DTFB+ recipes document Setup Geometry utility.

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1. J. C. Slater and G. F. Koster: "Simplified LCAO Method for the Periodic Potential Problem". 1954. Physical Review 94 (1498). DOI: 10.1103/PhysRev.94.1498.