Multidisciplinary Research Program of the University Research Initiative MURI

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Multidisciplinary Research Program of the
University Research Initiative (MURI)
Accurate Theoretical Predictions of the
Properties of Energetic Materials Donald L.
Thompson (PI) Department of Chemistry University
of Missouri Columbia
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Motivation
The need for more efficient, faster, and cheaper
methods for discovering new energetic
materials The Plan ? Develop theoretical
methods that can be used predict the critical
properties and behaviors of notional energetic
materials ? Provide theoretical guidance in the
development of new energetic materials ?
Better understanding of existing energetic
materials ? Advances in theoretical
computational methods
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OVERARCHING GOALS
Predictive capabilities for energetic materials
applicable to the chemical decomposition of
condensed-phase energetic materials under
extreme conditions to enhance our understanding
of current materials and aid in the design and
discovery of new ones. A practical method for
predicting solvation and separation in
supercritical fluids.
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Specific Goals

• Potentials that describe the inter- and
  intra-molecular forces,
• including phase transitions and chemical
  reactions.
• Ab initio predictions of structures and
  properties
• of solids at high temperatures and pressures.
• Methods to predict mechanical properties and
• physical changes in condensed phases.
• Methods to predict chemical decomposition
• in condensed phases, particularly ignition and
  sensitivity
• in response to heating and shocking.
• Methods for predicting temperatures of the
  condensed
• phases and flames resulting from physical and
  chemical
• changes, including a predictive model for the
  heat feedback
• from the flame to burning surface.
• Methods for predicting solvation and separation
  for energetic

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Advances in basic theoretical methods

• Advanced methods for ab initio treatments of
  condensed phase
• materials, including chemical changes
• Advanced methods for ab initio predictions of
  reaction energetics
• New methods for using ab initio quantum
  chemistry methods in
• conjunction with molecular dynamics methods
• General universal atomic-level potentials for
  describing complex
• chemical reaction, particularly for
  combustion of C,N,O,H systems.
• Accurate methods for predicting molecular
  solubility
• Improved practical methods for computing rates
• Improved methods for performing atomic-level
  simulations
• Methods for realistic simulations of chemistry
  in condensed phases

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Transitioning the Methods
There are ongoing interactions with and feedback
from the Army for the immediate transitioning of
methods and results for DoD applications We are
working closely with Dr. Betsy Rice to
immediately hand off new developments The
models and methods are being continuously tested
and incorporated into Army modeling codes.
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The Expertise
The MURI brings together the requisite expertise
to develop the theory, models, computational
methods, and computer codes for accurate
predictions of the properties and behaviors of
energetic materials.
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The MURI Team
John E. Adams (University of Missouri, Columbia)
Flame-Surface Heat Exchange Herman L. Ammon
(University of Maryland) Crystal Models Rodney
J. Bartlett (University of Florida) Ab Initio
Potential Energy Surfaces Donald W. Brenner
(North Carolina State University) Reactive
Potentials David M. Ceperley and Richard M.
Martin (University of Illinois,
Urbana-Champaign) Quantum Simulations of
Materials Donald L. Thompson (University of
Missouri, Columbia) Simulations and Rates
Christopher J. Cramer and Donald G. Truhlar
(University of Minnesota) Separation and
Solvation
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David M. Ceperley and Richard M.
MartinUniversity of Illinois, Urbana-Champaign

• Development of Fundamental Methods for Prediction
  of
• Properties of Materials Under Extreme Conditions
• Develop methods for first-principles
  simulations
• Provide benchmarks that can be used in
• constructing universal force field models

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Rodney J. BartlettUniversity of Florida

• Ab Initio Predictions for Potential Energy
  Surfaces
• for Chemical Reactions
• ? Develop better Q.M. methods for computing
• accurate PESs
• Provide critical data for the classical
  potentials
• ? Develop methods for direct dynamics

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Herman L. AmmonUniversity of Maryland

• Structure-Density-Heat of Formation-Sensitivity
  Predictions
• Develop procedures for predictions of crystal
  structures,
• densities and heats of formation of energetic
  materials
• Investigate the relationships between crystal
• structure/microstructure and sensitivity,
  compressibility,
• polymorphism and crystal shape
• Test procedures by predictions for known
  energetic
• materials

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Donald W. BrennerNorth Carolina State University

• Quantum-Based, Reactive Potentials for Simulating
  Shock
• Dynamics of Condensed-Phase Energetic Materials
• A Bridge between Ab Initio Calculations and
  Experimental
• Shock Dynamics
• Developing a transferable analytic reactive
  potential for C,H,O,N species,
• e.g., RDX HMX, based on a bond-order
  formalism and ab initio data that
• will enable large-scale, 3-D MD simulations
• ? Validating specific reaction paths and rates
• Will predict system properties related to shock
  initiation and detonation
• for a wide range of energetic materials
• Bridge molecular ab initio studies and the
  macroscale properties of shocked,
• condensed-phase energetic materials
• ? Validation of the potentials across length
  scales
• ? Initial focus Hydrazine, RDX and HMX.

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John E. AdamsUniversity of Missouri, Columbia

• Gas-Liquid Interactions Flame-Surface Heat
  Exchange
• Develop accurate models to aid in the prediction
  of the burning
• rate of solid-phase energetic materials
• Predictions of the temperature of the fluid
  layer that forms between
• the flame and the underlying solid surface
• Develop quantitative model for the energy
  feedback from
• flame to surface.
• Link the MURI condensed-phase models with the
  steady-state
• continuum model of Miller and Anderson

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Christopher J. Cramer and Donald G. Truhlar
University of Minnesota

• Prediction of Separation and Solvation Behavior
• ? Develop models for computing free energies of
  transfer
• of molecules between the gas phase, the
  liquid phase,
• and the solid phase, and into supercritical
  fluids.
• ? Base models on both semiempirical and
  first-principles
• methods
• Achieve a better understanding of the
  solubility and other
• properties of substances in supercritical
  fluids
• Employ that understanding to develop
  supercritical fluid
• technologies for recycling and reclamation of
  energetic
• materials

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