Analysis of carbon cluster formation during hightemperature decomposition of hmx and tatb with reaxff reactive molecular dynamics

The nitramine-based high explosive (HE) TATB is known to produce a large amount of high-molecular weight carbon-dominated clusters, while HE materials like HMX and RDX predominantly generate low-molecular weight products after detonation. To study the high-temperature dynamics of carbon cluster formation on an atomistic scale we have performed high-temperature dynamics simulation on crystalline HMX and TATB systems using the ReaxFF reactive force field. We found that our TATB simulations indeed resulted in the formation of a substantial carbon-dominated high-molecular weight phase, while HMX does almost exclusively generate small-molecule products. We have analyzed the kinetics and chemistry related to carbon cluster formation in TATB as well as the structure of the resulting carbon phase.