Atomistix ToolKit (ATK) is a commercial software for atomic-scale modeling and simulation of nanosystems. The software was originally developed by Atomistix A/S, and was later acquired by QuantumWise following the Atomistix bankruptcy.^[1] QuantumWise was then acquired by Synopsys in 2017.^[2]

Atomistix ToolKit is a further development of TranSIESTA-C, which in turn in based on the technology, models, and algorithms developed in the academic codes TranSIESTA,^[3] and McDCal,^[4] employing localized basis sets as developed in SIESTA.^[5]

Atomistix ToolKit combines density functional theory with non-equilibrium Green's functions for first principles electronic structure and transport calculations of

• electrode—nanostructure—electrode systems (two-probe systems)
• molecules
• periodic systems (bulk crystals and nanotubes)

The key features are

• Calculation of transport properties of two-probe systems under an applied bias voltage
• Calculation of energy spectra, wave functions, electron densities, atomic forces, effective potentials etc.
• Calculation of spin-polarized physical properties
• Geometry optimization
• A Python-based NanoLanguage scripting environment

• Atomistix Virtual NanoLab — a graphical user interface
• NanoLanguage
• Atomistix
• Quantum chemistry computer programs
• Molecular mechanics programs