TBSTUDIO

Official Resources

• Homepage: https://tight-binding.com/
• Repository: https://github.com/mohammadnakhaee/tbstudio
• License: Academic/Commercial (See Website)

Overview

TBSTUDIO is a comprehensive software package centered around a graphical user interface (GUI) for the construction of tight-binding Hamiltonians from first-principles data. It simplifies the often complex workflow of fitting Slater-Koster parameters to Density Functional Theory (DFT) band structures. By automating the fitting process and providing visualization tools, it serves as a bridge between ab initio codes (like VASP, Quantum ESPRESSO) and model analysis tools.

Scientific domain: Materials Modeling, Band Structure Fitting Target user community: Materials scientists needing to extract effective models from DFT

Theoretical Methods

• Slater-Koster Formalism: Parameterization of hopping integrals based on orbital symmetries ($ss\sigma$, $pp\pi$, etc.).
• Fitting Algorithm: Levenberg-Marquardt non-linear least squares optimization to minimize the difference between DFT and TB eigenvalues.
• Basis Sets: Support for orthogonal and non-orthogonal bases.
• Spin-Orbit Coupling: Inclusion of atomic SOC parameters.

Capabilities

• Model Generation:
  • Auto-fit bands from VASP/QE/Wien2k.
  • Generates Slater-Koster hopping tables.
• Visualization:
  • 3D rendering of the crystal structure and orbital positions.
  • Interactive plots comparing DFT and fitted TB bands.
• Exports:
  • Python (Pybinding compatible output).
  • MATLAB, C++, Fortran, Mathematica.
  • Raw Hamiltonian matrices.

Key Strengths

• GUI-Driven: Makes the sophisticated task of tight-binding parameterization accessible to users without deep coding experience.
• Cross-Platform: Runs on Windows, Linux, and macOS.
• Integration: Designed to feed into widely used solvers like Pybinding or Green's function codes.

Inputs & Outputs

• Inputs:
  • Crystal structure (POSCAR, CIF).
  • Band structure data (EIGENVAL).
• Outputs:
  • Fitted parameter files.
  • Source code defining the model in various languages.

Interfaces & Ecosystem

• Upstream: VASP, Quantum ESPRESSO, Abinit, Wien2k.
• Downstream: Pybinding, Kwant (via script), custom codes.

Performance Characteristics

• Efficiency: Fitting is performed locally; speed depends on the number of orbitals and k-points fitted.
• Usability: Interactive feedback loop significantly speeds up the model generation process compared to command-line fitting tools.

Comparison with Other Codes

• vs. Wannier90: Wannier90 is the gold standard for exact (interpolated) tight-binding models. TBSTUDIO uses the Slater-Koster approximation, which is less exact but physically more intuitive (fewer, longer-range parameters) and often transfers better to varying geometries.
• vs. PythTB: PythTB is a library for using models. TBSTUDIO is a tool for creating them.

Application Areas

• Heterostructures: Creating transferrable models for interface calculations.
• Device Simulation: Generating input Hamiltonians for transport codes.

Community and Support

• Development: Mohammad Nakhaee.
• Source: GitHub / Website.

Verification & Sources

• Website: https://tight-binding.com/
• Primary Publication: M. Nakhaee et al., arXiv:1910.02917.
• Verification status: ✅ VERIFIED
  • Active tool with commercial/academic licensing dual model.