There is an increasing urgency to find stable and lightweight hydrogen storage materials for clean transport applications. Promising options being investigated include Mg-based alloys, metal-borohydrides, alanates and amido-boranes. However, many of these materials suffer from poor kinetics and high enthalpies of formation which require high operation temperatures. Solution processing of complex hydrides can help to overcome these problems, are are therefore coming into focus. In this proposal we will use neutron diffraction in conjunction with H/D substitution and EPSR analysis to measure and understand the structure of ammonia borane (AB) in solution. Samples will be prepared at 10 and 20 wt % AB in: water, dimethylsulphoxide, and tetrahydrofuran. Selective deuteration of solvent and 11B/D-enrichment of AB will enable the local and intermediate range structure to be determined.