Over the past few years, the use of real-time time-dependent DFTB (RT-TDDFTB) has attracted significant attention as a promising approach for extending the DFTB formalism to the non-equilibrium electron dynamics of extremely large chemical systems. As specific examples, this method has been used to calculate photo-injection dynamics in dye-sensitized TiO 2 solar cells, optical properties of photosynthetic pigments, molecular aggregates, graphene nanoflakes, DNA intercalation complexes, manybody interactions in solvated nanodroplets, and excitation energy transfer dynamics in plasmonic arrays. To carry out an RT-TDDFTB dynamics calculation, one must first compute the ground-state Hamiltonian, overlap matrix elements, and the initial single-electron density matrix within the self-consistent DFTB approach. The open-source DFTB+ code provides a practical way to obtain these quantities, and a more detailed description of ground-state DFTB can be found in previous publications. Once the ground-state Hamiltonian, overlap matrix elements, and the initial single-electron density matrix are calculated, they can be used as initial input conditions in subsequent real-time quantum dynamics calculations. These RT-TDDFTB quantum dynamics calculations are carried out in practice by applying a time-dependent electric field to the initial ground state density matrix, resulting in the Hamiltonian