Tight Binding Studio is a quantum technical software package to construct Tight Binding (TB) model for nano-scale materials. Starting from the simplified linear combination of atomic orbitals method in combination with first-principles calculations (such as OpenMX or Vasp packages), one can construct a TB model in the two-center approximation. Using Slater and Koster approach we calculate the TB Hamiltonian of the system and use a nonlinear fitting algorithm to find the best entries for both Hamiltonian and overlap matrices to reproduce the first-principles data. One can obtain expressions for the Hamiltonian and overlap matrix elements between different orbitals (s, p and d orbitals with or without spin-orbit coupling) for the different atoms and present the SK coefficients in an orthogonal or nonorthogonal basis set. Furthermore, by using TBStudio you can generate your own code in your preferred programming language ie. C++, C, Fortran, Mathematica, Matlab, and Python.

What is the Tight Binding model?

In fact, a TB model is an effective Hamiltonian for an interacting electron system that can be a lattice of a very widely spaced atoms. In a simple non-interacting picture, the overlap of the outermost electrons leads to a hybridization of the electronic orbitals and leads to the de-localization of Bloch states.

Read more about TB model here.

Tight-Binding (TB) approaches is based on the LCAO method that is primarily used to calculate the band structure and single-particle Bloch states of a typical material as e.g. done by Slater and Koster. The tight-binding method is simple and computationally very fast. Therefore, it is often used in calculations of very large systems, with more than a few thousand atoms in the unit cell. TB Hamiltonian gives the electronic structure of a system using a real-space picture of the system. The real Hamiltonians provide insight into the nature of the transport mechanisms.