Ultrafast electronic and nuclear imaging of ammonia with electron diffraction

We demonstrate the simultaneous and direct imaging of electron and hydrogen dynamics during a photochemical reaction. In ammonia (NH₃), the substantial role of the valence electronic structure leads to the breakdown of the independent atom model for molecular scattering. Using an ultrafast electron diffraction (UED) probe, we make use of this to follow concerted dynamics involving the electronic and nuclear degrees of freedom following photoexcitation.