title: Dynamic transition in the structure of an energetic crystal during chemical reactions at shock front prior to detonation.
abstract: Mechanical stimuli in energetic materials initiate chemical reactions at shock fronts prior to detonation. Shock sensitivity measurements provide widely varying results, and quantum-mechanical calculations are unable to handle systems large enough to describe shock structure. Recent developments in reactive force-field molecular dynamics (ReaxFF-MD) combined with advances in parallel computing have paved the way to accurately simulate reaction pathways along with the structure of shock fronts. Our multimillion-atom ReaxFF-MD simulations of l,3,5-trinitro-l,3,5-triazine (RDX) reveal that detonation is preceded by a transition from a diffuse shock front with well-ordered molecular dipoles behind it to a disordered dipole distribution behind a sharp front.
authors.affiliation: Collaboratory for Advanced Computing and Simulations, Department of Chemical Engineering & Materials Science, University of Southern California, Los Angeles, CA 90089-0242, USA.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Nomura
authors.forename: Rajiv K
authors.initials: RK
authors.lastname: Kalia
authors.forename: Aiichiro
authors.initials: A
authors.lastname: Nakano
authors.forename: Priya
authors.initials: P
authors.lastname: Vashishta
authors.forename: Adri C T
authors.initials: AC
authors.lastname: van Duin
authors.forename: William A
authors.initials: WA
authors.lastname: Goddard