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Title: Extended Lagrangian Born-Oppenheimer molecular dynamics simulations of the shock-induced chemistry of phenylacetylene

The initial chemical events that occur during the shock compression of liquid phenylacetylene have been investigated using self-consistent tight binding molecular dynamics simulations. The extended Lagrangian Born-Oppenheimer molecular dynamics formalism enabled us to compute microcanonical trajectories with precise conservation of the total energy. Our simulations revealed that the first density-increasing step under shock compression arises from the polymerization of phenylacetylene molecules at the acetylene moiety. The application of electronic structure-based molecular dynamics with long-term conservation of the total energy enabled us to identify electronic signatures of reactivity via monitoring changes in the HOMO-LUMO gap, and to capture directly adiabatic shock heating, transient non-equilibrium states, and changes in temperature arising from exothermic chemistry in classical molecular dynamics trajectories.
Authors:
;  [1] ;  [2]
  1. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
  2. Weapons Experiments Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
Publication Date:
OSTI Identifier:
22416126
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 6; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACETYLENE; BORN-OPPENHEIMER APPROXIMATION; CHEMISTRY; COMPRESSION; COMPUTERIZED SIMULATION; DENSITY; ELECTRONIC STRUCTURE; LAGRANGIAN FUNCTION; LIQUIDS; MOLECULAR DYNAMICS METHOD; MOLECULES; POLYMERIZATION; REACTIVITY; SHOCK HEATING; TOLAN; TRANSIENTS