Dynamics of the High-Pressure Phase Transition in 2,4,6-triamino-1,3,5-trinitrobenzene (TATB)

Understanding the sensitivity and performance of energetic materials (EMs) requires information on how they respond under extreme conditions. TATB is an insensitive crystalline EM with graphitic-like layers and a resilient 2D intermolecular hydrogen bonded network. Recent static compression diamond anvil cell experiments combined with first-principles calculations found evidence it undergoes a high-pressure phase transition that involves sliding of its graphitic layers. Layer sliding alters the stacking motif and leads to a transition from a triclinic to monoclinic unit cell. In this work, the dynamics of the phase transition under pressure are investigated using density functional theory and a classical force field. Assessments of the thermodynamic drivers and kinetic barriers for the transition are discussed.