In this paper we propose an extension of the self-consistent charge-density-functional tight-binding ~SCCDFTB! method @M. Elstner et al., Phys. Rev. B 58, 7260 ~1998!#, which allows the calculation of the optical properties of finite systems within time-dependent density-functional response theory ~TD-DFRT!. For a test set of small organic molecules low-lying singlet excitation energies are com...

We predict structures and energies of water clusters containing up to 100 waters with tight-binding density functional theory (DFTB). A per-hydrogen-bond energy correction is found to correct for systematic errors in the DFTB cluster energies. We compare the DFTB structures and energies to density functional theory (DFT) calculations and to the most accurate wave function theoretical (WFT) valu...

A nonadiabatic molecular dynamics is implemented in the framework of the time-dependent density functional tight binding method (TDDFTB) combined with Tully's stochastic surface hopping algorithm. The applicability of our method to complex molecular systems is illustrated on the example of the ultrafast excited state dynamics of microsolvated adenine. Our results demonstrate that in the presenc...