PETN under pressure

Abstract. The performance of energetic materials is commonly linked to their crystal structure, which is well known to be affected by changing pressure and temperature. An energetic whose changing properties under pressure have not been widely studied is pentaerythritol tetranitrate (PETN). PETN is an impact sensitive explosive, commonly used as a part of plastic bonded explosives, including SEMTEX. As part of our study, experimental high-pressure neutron powder diffraction experiments were undertaken and showed changes in the behaviour of PETN around 4GPa. However, these are difficult to explain experimentally, so computational modelling can be used to help understand any structural changes and their effects. The computational work presented here will investigate changes in structure and vibrational spectra of PETN with up to 11GPa of applied pressure and evaluate how these changes can explain variations in properties, including sensitivity, under applied pressure.