  An ab initio quantum-classical mixed scheme for the time evolution of
electrode-device-electrode systems is introduced to study nuclear dynamics in
quantum transport. Two model systems are discussed to illustrate the method.
Our results provide the first example of current-induced molecular desorption
as obtained from a full time-dependent approach and suggest the use of ac
biases as a way to tailor electromigration. They also show the importance of
non-adiabatic effects for ultrafast phenomena in nanodevices.
