Abstract: The “perfect” and defective cocrystal models with adulteration, vacancy and dislocation are established to investigate the influence of crystal defect on stability, sensitivity, detonation performance and mechanical property of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)/ 3-nitro-1,2,4-triazol-5-one (NTO) cocrystal explosive. Molecular dynamics method is applied to predict the properties of the proposed crystal models. The binding energy, bond length distribution of trigger bond, interaction energy of trigger bond, cohesive energy density, detonation parameters and mechanical properties were obtained and compared. The results show that the binding energy of explosive is declined and its stability is weakened due to the influence of crystal defect. The maximum trigger bond length of defective crystal model is increased, while the interaction energy of trigger bond and the cohesive energy density are decreased, meaning that the sensitivity of explosive is increased and its safety is worsened. The density, detonation velocity and detonation pressure of defective crystal model are declined, indicating that the energy density and power are lessened. Compared with the “perfect” crystal model, the tensile modulus, bulk modulus and shear modulus of defective crystal model are decreasaed, and Cauchy pressure is increased, namely, the rigidity and stiffness are declined and the plastic property and ductility are increased.Key

Key words: cocrystalexplosive, crystaldefect, stability, sensitivity, detonationperformance, mechanicalproperty, moleculardynamics