We ask for 7 days on IRIS to study the quasielastic scattering in ammonium borohydride (NH4BH4). Using enriched ND4 and BD4, we aim to separate out the difference rotational and tunnelling behaviour associated with the ammonium and borohydride ions. We already have performed a DFT-MD study of NH4BH4 which show a very distinctive difference in rotational behaviour between cation and anion. Our objective is to correlate the QENS and DFT-MD analyses to obtain a better understanding of the orientational disorder in this prototypic material. This will also help us to understand the nature of the extensive intermolecular dihydrogen bonding which is responsible for the high melting point of ammonium borohydride (300K) compared with methane (90K). This, in turn, will inform us about the hydrogen decomposition mechanisms of this highest of wt% solid-state hydrogen storage materials.