MOLECULAR-DYNAMICS STUDY OF DETONATION .2. THE REACTION-MECHANISM

In this work, we investigate mechanisms of chemical reactions that sus tain an unsupported detonation. The chemical model of an energetic cry stal used in this study consists of heteronuclear diatomic molecules t hat, at ambient pressure, dissociate endothermically. Subsequent assoc iation of the products to form homonuclear diatomic molecules provides the energy release that sustains the detonation. A many-body interact ion is used to simulate changes in the electronic bonding as a functio n of local atomic environment. The consequence of the many-body intera ction in this model is that the intramolecular bond is weakened with i ncreasing density. The mechanism of the reaction for this model was ex tracted by investigating the details of the molecular properties in th e reaction zone with two-dimensional molecular dynamics. The mechanism for the initiation of the reaction in this model is pressure-induced atomization. There was no evidence of excitation of vibrational modes to dissociative states. This particular result is directly attributabl e to the functional form and choice of parameters for this model, but might also have more general applicability.