  We present dynamical transport calculations based on a tight-binding
approximation to adiabatic time-dependent density functional theory (TD-DFTB).
The reduced device density matrix is propagated through the Liouville-von
Neumann equation. For the model system, 1,4-benzenediol coupled to aluminum
leads, we are able to confirm the equality of the steady state current
resulting from a time-dependent calculation to a static calculation in the
conventional Landauer framework. We also investigate the response of the
junction subjected to alternating bias voltages with frequencies up to the
optical regime. Here we can clearly identify capacitive behaviour of the
molecular device and a significant resonant enhancement of the conductance. The
results are interpreted using an analytical single level model comparing the
device transmission and admittance. In order to aid future calculations under
alternating bias, we shortly review the use of Fourier transform techniques to
obtain the full frequency response of the device from a single current trace.

Mesoscale and Nanoscale Physics