The solid solution between lithium amide and lithium imide plays important roles in both ammonia decomposition catalysis and solid state hydrogen storage. In order to understand the stoichiometry-dependent function of the system, an elucidation of the variation in the structure of the solid solution across the stoichiometry range between amide and imide is necessary. It has already been observed that there are significant differences in structure depending on the synthesis method used. As part of a systematic investigation of the structure and properties of the lithium amide-imide solid solution, we request one day of experimental time on POLARIS to measure neutron powder diffraction data of a series of non-stoichiometric samples from this system. This will allow the development of structural models for non-stoichiometry in the system.