Atomic mean square displacement study of the bond breaking mechanism of energetic materials before explosive initiation

Understanding and predicting the bond breaking mechanism of energetic materials before explosion initiation is one of the huge challenges in explosion science. By means of the mean square displacement of the atom from the equilibrium position and theoretical bond breaking tensile change of the chemical bond, we establish a new criterion to judge whether the chemical bond is broken. Further, α-RDX is used as the verification object to verify the accuracy of this model. We obtained an initial decomposition temperature of 434-513 K for α-RDX at 0 GPa, and the initial bond breaking type was N-NO₂. Finally, based on this model, we discussed in detail the breaking of chemical bonds of solid nitromethane near the detonation pressure. We think that the high temperature and high pressure caused by the shock wave may break all the chemical bonds of nitromethane near the detonation pressure.