DFTB+, a software package for efficient approximate density functional theory based atomistic simulations

Area of Science:

• Computational Chemistry
• Materials Science
• Quantum Mechanics

Background:

• Atomistic simulations are crucial for understanding material properties.
• Traditional quantum mechanical methods can be computationally expensive for large systems.
• Approximations to Density Functional Theory (DFT) offer a balance between accuracy and efficiency.

Purpose of the Study:

• To provide an overview of the capabilities of the DFTB+ software package.
• To highlight recent developments and new features in DFTB+.
• To demonstrate the utility of DFTB+ through use case examples.

Main Methods:

• Implementation of Density Functional Tight Binding (DFTB) and related methods.
• Approximation of DFT extensions, including hybrid functionals.
• Utilizing non-equilibrium Green's functions for electron transport simulations.

Main Results:

• DFTB+ enables fast and efficient simulations of large systems and long timescales.
• The software supports various DFT approximations and extensions.
• DFTB+ can be used as a standalone application, library, or calculation server.

Conclusions:

• DFTB+ is a versatile tool for atomistic simulations, offering speed and reasonable accuracy.
• Recent developments have expanded its capabilities for excited states and electron transport.
• Ongoing developments aim to further enhance its performance and applicability.