Void Effects on Thermal Decomposition of 3,4-Bis(3-nitrofurazan-4-yl)furoxan: A Deep Potential Molecular Dynamics Study

Abstract Void defect represents unavoidable microscopic defect in energetic materials, yet its influence on thermal decomposition remains poorly understood at the atomic level. In this paper, deep potential molecular dynamics (DPMD) simulations were employed to investigate the influence of void defects as internal interfaces on the thermal decomposition of 3,4-bis(3-nitrofurazan-4-yl)furoxan (DNTF). The results show that the thermal decomposition of DNTF consists of two exothermic stages. Void defects accelerate the initial decrease in potential energy, whereas the lower density associated with voids delays the second decrease. Voids promote the breaking of C–N and C–C bonds, thereby accelerating DNTF decomposition. In addition, voids enhance the mobility of surrounding atoms, with the double-void configuration (S3) exhibiting stronger promoting effect than the single large void (S1). Voids also induce more pronounced temperature fluctuations in the surrounding region, particularly in S1. Void defects do not alter the decomposition pathway of DNTF, and the ring-opening reaction of the furoxan remains the earliest decomposition pathway. The activation energy of S1 is 98.1 kJ/mol through DPMD, which is lower than that of the perfect crystal. Under multiple computational methods (FWO, KAS and AIC), the comparison results between Small S1 and Small S2 also demonstrate that the presence of voids consistently yields lower activation energy values. The experimental activation energy is 121.4 kJ/mol using the Kissinger method. The decomposition products consist of CO2, NO, NO2 and N2O, which are consistent with past experiments.