TDDFTB
TDDFTB, or time-dependent density functional tight-binding, is an approximate quantum-chemical method for calculating electronic excited states in large systems. It extends density functional tight-binding (DFTB) to the time-dependent regime by applying linear-response theory to the ground-state DFTB electronic structure, yielding excitation energies and oscillator strengths with much lower computational cost than standard TD-DFT.
The method uses a minimal valence basis and a parameterized Hamiltonian derived from a second-order expansion
TDDFTB is particularly suited for large molecules, polymers, and nanostructures, where it can handle systems containing
Limitations include dependence on the underlying parameterization and the approximate kernel, which can limit accuracy for