Recent Developments in DFTB+, a Software Package for Efficient Atomistic Quantum Mechanical Simulations
B. Hourahine, Matías Berdakin, J. A. Bich, Franco P. Bonafé, Cristopher Camacho, Qiang Cui, Megan Y. Deshaye, Gonzalo Díaz Mirón, Sebastian Ehlert, Marcus Elstner, Thomas Frauenheim, Nir Goldman, Roberto Andrés González León, Tammo van der Heide, Stephan Irle, Tim Kowalczyk, Tomáš Kubař, In Seong Lee, Carlos R. Lien-Medrano, Alexander A. Maryewski, Tobias Melson, Seung Kyu Min, Thomas A. Niehaus, Anders M. N. Niklasson, Alessandro Pecchia, Karsten Reuter, Cristián G. Sánchez, Christoph Scheurer, Michael A. Sentef, P. V. Stishenko, Van‐Quan Vuong, Bálint Aradi
Abstract
DFTB+ is a flexible, open-source software package developed by its community, designed for fast and efficient atomistic quantum mechanical simulations. It employs various methods that approximate density functional theory (DFT), such as density functional-based tight binding (DFTB) and the extended tight binding (xTB) approach allowing simulations of large systems over extended time scales with reasonable accuracy, while being significantly faster than traditional ab initio methods. In recent years, several new extensions of the DFTB method have been developed and implemented in the DFTB+ program package in order to improve the accuracy and generality of the available simulation results. In this paper, we review those enhancements, show several use case examples and discuss the strengths and limitations of its features.