title: Atomistic simulation of orientation dependence in shock-induced initiation of pentaerythritol tetranitrate.
abstract: The dependence of the reaction initiation mechanism of pentaerythritol tetranitrate (PETN) on shock orientation and shock strength is investigated with molecular dynamics simulations using a reactive force field and the multiscale shock technique. In the simulations, a single crystal of PETN is shocked along the [110], [001], and [100] orientations with shock velocities in the range 3-10 km/s. Reactions occur with shock velocities of 6 km/s or stronger, and reactions initiate through the dissociation of nitro and nitrate groups from the PETN molecules. The most sensitive orientation is [110], while [100] is the most insensitive. For the [001] orientation, PETN decomposition via nitro group dissociation is the dominant reaction initiation mechanism, while for the [110] and [100] orientations the decomposition is via mixed nitro and nitrate group dissociation. For shock along the [001] orientation, we find that CO-NO(2) bonds initially acquire more kinetic energy, facilitating nitro dissociation. For the other two orientations, C-ONO(2) bonds acquire more kinetic energy, facilitating nitrate group dissociation.
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA. tnshan@sandia.gov
authors.forename: Tzu-Ray
authors.initials: TR
authors.lastname: Shan
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Wixom
authors.forename: Ann E
authors.initials: AE
authors.lastname: Mattsson
authors.forename: Aidan P
authors.initials: AP
authors.lastname: Thompson