The aim of this proposal is to measure inelastic neutron spectra using the TOSCA instrument for a selection of energetic materials including some polymorphs of HMX, CL-20, and ammonium nitrate. These measurements will be made under ambient conditions using standard sample environments, but we will also explore the feasibility of conducting future experiments at elevated pressures. The INS spectra obtained will be compared with the results of computational studies and will increase our understanding of energy transfer within these materials. This has signiificance for their performance and for properties such as sensitivity to initiation. We will also explore whether there are any differences in the INS spectra between conventional RDX and resduced-sensitivity RDX. If so, this will provide insight into the fundamental reasons for the observed senistivity differences.