High-pressure structural studies of energetic materials

This article reviews how the advances in the techniques for the collection and analysis of high-pressure X-ray and neutron diffraction data, augmented by spectroscopic data, now permit the accurate determination of the full crystal structure of energetic materials under extreme conditions. Using these methods, the crystal structure of the high-pressure gamma-form of RDX (1,3,5-trinitrohexahydro-striazine) has been determined - the first case of a high-pressure structure of an energetic material. In addition, the crystal structure of the highly metastable beta-form has been determined and, contrary to the previous reports, has been shown to be different from the form obtained at elevated temperatures and pressures.