In this proposal we aim to understand the solvation of AB by two of the most important solvents ? ammonia and THF. Neutron diffraction is a key technique in this context because we can apply isotope labelling via H/D and N/15N. This will enable us to understand the AB solute-solute interactions and AB solvation. Open questions include the relative orientation of AB molecules and the existence or otherwise of solvent separated species. This information is not available from any other source. Our ultimate goal is to relate this structural data to hydrogen release and AB dehydrogenation and regeneration. We propose to study ammonia borane (AB) solutions in ammonia and THF at ~220K and concentrations of 5 and 20% by weight AB on SANDALS. In each case we will make solutions of AB D6-11B, H6-11B and a mix in labelled solvents.