Nuclear dynamics in the core-excited state of aqueous ammonia probed by resonant inelastic soft x-ray scattering

The electronic structure of aqueous NH₃ and ND₃ has been investigated using resonant inelastic soft x-ray scattering. Spectral features of different processes involving nuclear dynamics in the core-excited state can be identified. When exciting into the lowest core-excited state, we find a strong isotope effect and clear evidence for ultrafast proton dynamics. Furthermore, a strong vibronic coupling is observed and, in the case of aqueous NH₃, a vibrational fine structure can be resolved.