We investigate time-dependent electron transfer (ET) in benchmark
donor-bridge-acceptor systems. For the small bridge sizes studied, we obtain
results far different from the perturbation theory which underlies
scattering-based approaches, notably a lack of destructive interference in the
ET for certain arrangements of bridge molecules. We also calculate wavepacket
transmission in the non-steady-state regime, finding a featureless spectrum,
while for the current we find two types of transmission: sequential and direct,
where in the latter, the current transmission increases as a function of the
energy of the transferred electron, a regime inaccessible by conventional
scattering theory.Comment: replacement of arXiv:1603.07715, revised and title change