The tight binding method is an approximate approach for solving for the electronic wave functions for electrons in solids assuming a basis of localized atomic-like orbitals. We assume here that the orbitals are orthonormal, and focus on the “empirical tight binding” approach in which the Hamiltonian matrix elements are simply parametrized, as opposed to being computed ab-initio.
The PythTB package is intended to set up and solve tight-binding models for the electronic structure of
1D chains and ladders
2D layers (square lattice, hexagonal lattice, honeycomb lattice, etc.)
clusters, ribbons, slabs, etc., cut from higher-dimensional crystals
As currently written, it is not intended to handle realistic chemical interactions. So for example, the Slater-Koster forms for interactions between s, p and d orbitals are not currently coded, although the addition of such features cou