We ask for 1 day on HRPD to study the aristotype disordered rock-salt phase of ammonium borohydride. Our goal is to determine accurate cubic harmonic parameters to determine the nature of the cation and anion molecular orientational disorder and to compare our diffraction analysis with recently completed DFT molecular dynamics. Preliminary multisite diffraction analysis of low-Q WISH data broadly confirm the distinct difference between NH4 and BD4 orientational disorder. We require resolved diffraction data below 0.4A to compare diffraction and DFT-MD cubic harmonic analyses which will subsequently enable us to explore the DFT-MD with confidence to understand the nature of both the orientational hopping and also the complex dihydrogen bonding in this prototypic hydrogen storage material.