DFTB+ is a versatile community developed open source software package offering fast and efficient methods for carrying out atomistic quantum mechanical simulations. By implementing various methods approximating density functional theory (DFT), such as the density functional based tight binding (DFTB) and the extended tight binding method, it enables simulations of large systems and long timescales with reasonable accuracy while being considerably faster for typical simulations than the respective ab initio methods. Based on the DFTB framework, it additionally offers approximated versions of various DFT extensions including hybrid functionals, time dependent formalism for treating excited systems, electron transport using non-equilibrium Green’s functions, and many more. DFTB+ can be used as a user-friendly standalone application in addition to being embedded into other software packages as a library or acting as a calculation-server accessed by socket communication. We give an overview of the recently developed capabilities of the DFTB+ code, demonstrating with a few use case examples, discuss the strengths and weaknesses of the various features, and also discuss on-going developments and possible future perspectives.

中文翻译：

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DFTB+，基于原子模拟的高效近似密度泛函理论软件包


DFTB+ 是一个多功能社区开发的开源软件包，提供快速有效的方法来进行原子量子力学模拟。通过实施各种近似密度泛函理论 (DFT) 的方法，例如基于密度泛函的紧束缚 (DFTB) 和扩展紧束缚方法，它能够以合理的精度对大型系统和长时间尺度进行仿真，同时比典型仿真要快得多相应的从头开始方法。基于 DFTB 框架，它还提供了各种 DFT 扩展的近似版本，包括混合泛函、用于处理激发系统的时间相关形式主义、使用非平衡格林函数的电子传输等等。除了作为库嵌入到其他软件包中或充当通过套接字通信访问的计算服务器之外，DFTB+ 还可以用作用户友好的独立应用程序。我们概述了 DFTB+ 代码最近开发的功能，并通过一些用例示例进行了演示，讨论了各种功能的优点和缺点，还讨论了正在进行的开发和未来可能的前景。