Reactive molecular dynamics simulations on the thermal decompositions and oxidations of TKX-50 and twinned TKX-50

To study the influence of twinned crystals on the performance of TKX-50, normal TKX-50 (N-TKX-50) and twinned TKX-50 (T-TKX-50) supercells are constructed, and ReaxFF-Ig reactive molecular dynamics simulations are performed to study the thermal decomposition and oxidation of N-TKX-50 and T-TKX-50 at 1000, 2000 and 3000 K. The mechanism of thermal decomposition and oxidation of N-TKX-50 and T-TKX-50 are analyzed in terms of potential energy evolution, primary reaction paths, and the intermediate and final products. We find that T-TKX-50 possesses higher decomposition and consumption rate than NTKX-50 at the same temperature conditions, while the decomposition and the oxidation end-products of N-TKX-50 and T-TKX-50 are the same. These results confirm that the T-TKX-50 crystal is unfavorable for the thermal stability of TKX-50. We believe that this work can provide some guidance for investigating the decomposition and oxidation of other materials.