Simulation of processes on the nanometer scale using the DFTB method

Thomas Heine, thomas.heine@chemie.tu-dresden.de, Physikalische Chemie,
Technische Universität Dresden, Dresden, D-01062, Germany

Many processes involve a change of structural topology, i.e. bond breaking and
bond formation. To treat those \u2013 at least qualitatively \u2013 correctly,
it is necessary to include quantum mechanics in the simulation technique. With
the density-functional based tight-binding method (DFTB) we are able to perform
such simulations, both on the nano meter and on the nano second scales.

In this paper, I will briefly present a modern implementation of DFTB. This
method has been applied in various computer simulations of processes in
materials. They include the study of the rupture process of a MoS2 inorganic
nanotube (see figure), where simulation and experimental tensile stress tests
agree on the mechanical properties of these tubes. Furthermore, I will present
calculations of the diffusion coefficients in molten halides, a simulation of
the 13C NMR pattern of Sc3NC80 and the evaluation of the stability of several
fullerites based on lower fullerenes C20, C28 and C50.