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

Abstract

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.

Electronic conductance and thermopower of single-molecule junctions of oligo(phenyleneethynylene) derivatives

“…Electronic transport properties of the OPE3 derivatives were computed using Non-Equilibrium Green's Function Theory based on the Density Functional Based Tight-Binding Method (DFTB) [38][39][40] as implemented in DFTB+ version 19.1. 41 DFTB is an approximate DFT method with an appealing cost/accuracy ratio and has been successfully used in a variety of applications in the field of molecular electronics. [42][43][44] Here we employed the auorg-0-1 Slater-Koster set 45,46 with orbital dependent Hubbard parameters and used a periodic setup, where the device is replicated perpendicular to the transport direction along the surface.…”

SARS-CoV-2 Virion Stabilization by Zn Binding

“…A more realistic description of Zn–protein interactions, especially when Zn-S bonds occur, requires polarizable or reactive force fields (Zhang et al, 2012 ; Li and Merz, 2017 ). Semiempirical quantum mechanics methods, like those driven by the density-functional tight-binding approximated (DFTB) hamiltonian (Elstner et al, 1998 ), include polarization and charge transfer in the calculation of atomic forces and allow energy minimization of systems of thousands of atoms within periodic boundary conditions (Hourahine et al, 2020 ). In this subsection we explore the energy profile around the previously selected configurations, using a DFTB hamiltonian.…”

“…The final configurations were then used as the initial configurations in the CG energy minimization performed with the DFTB hamiltonian. The DFTB+ code (Hourahine et al, 2020 ) was used with the znorg-0-1 parametrization (Moreira et al, 2009 ). The energy is assumed to be in a minimum when the maximal force component was lower than 0.01 Ha/Bohr.…”

Periodic DFT Calculations—Review of Applications in the Pharmaceutical Sciences

“…CASTEP [27] PW + a,b,c,d free energy, enthalpy, entropy, heat capacity, Debye temperature + * Academic, commercial DMol3 [28] NAO + b free energy, enthalpy, entropy, heat capacity, heats of formation, + Commercial DFTB+ [29] NAO, STO + a,b free energy, enthalpy, entropy, heat capacity, heats of formation + * Free, Lesser General Public License (LGPL) Quantum Espresso [30] PW + a,b, [34] PW + a,b,d free energy, enthalpy, entropy, heat capacity + * Academic, commercial CP2K [35] GTO, PW + a,b free energy, enthalpy, entropy + Free, General Public License (GPL)…”