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A transient semimetallic layer in detonating nitromethane

Abstract

Despite decades of research, the microscopic details and extreme states of matter found within a detonating high explosive have yet to be elucidated. Here we present the first quantum molecular-dynamics simulation of a shocked explosive near detonation conditions. We discover that the wide-bandgap insulator nitromethane (CH3NO2) undergoes chemical decomposition and a transformation into a semimetallic state for a limited distance behind the detonation front. We find that this transformation is associated with the production of charged decomposition species and provides a mechanism to explain recent experimental observations.

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Figure 1: Simulations of a 6.5 km s−1 shock in nitromethane with eight and 16 molecules in the computational cell.
Figure 2: Snapshots during a 16-molecule simulation.
Figure 3: Electronic density of states for a sequence of times.
Figure 4: Electronic state overlap parameter nc1/3aeff for a sequence of times.

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References

  1. Kramer, D. A. United States Geological Survey 2005 Minerals Yearbook. http://minerals.usgs.gov/minerals/pubs/commodity/ explosives/index.html#myb (2006).

  2. Gilman, J. J. Chemical-reactions at detonation fronts in solids. Phil. Mag. B 71, 1057–1068 (1995).

    Article  ADS  Google Scholar 

  3. Gilman, J. J. Mechanochemistry. Science 274, 65–65 (1996).

    Article  ADS  Google Scholar 

  4. Williams, F. Electronic states of solid explosives and their probable role in detonations. Adv. Chem. Phys. 21, 289–302 (1971).

    Google Scholar 

  5. Kuklja, M. M. & Kunz, A. B. Ab-initio simulation of defects in energetic materials: Hydrostatic compression of cyclotrimethylene trinitramine. J. Appl. Phys. 86, 4428–4434 (1999).

    Article  ADS  Google Scholar 

  6. Reed, E. J., Joannopoulos, J. D. & Fried, L. E. Electronic excitations in shocked nitromethane. Phys. Rev. B 62, 16500–16509 (2000).

    Article  ADS  Google Scholar 

  7. Elstner, M. et al. Self-consistent-charge density-functional tight-binding method for simulations of complex materials properties. Phys. Rev. B 58, 7260–7268 (1998).

    Article  ADS  Google Scholar 

  8. Reed, E. J., Fried, L. E. & Joannopoulos, J. D. A method for tractable dynamical studies of single and double shock compression. Phys. Rev. Lett. 90, 235503 (2003).

    Article  ADS  Google Scholar 

  9. Reed, E. J., Fried, L. E., Manaa, M. R. & Joannopoulos, J. D. in Chemistry at Extreme Conditions (ed. Manaa, M. R.) 297–326 (Elsevier, New York, 2005).

    Book  Google Scholar 

  10. Reed, E. J., Fried, L. E., Henshaw, W. D. & Tarver, C. M. Analysis of multi-scale simulation technique for stead shock waves in materials with analytical equations of state. Phys. Rev. E 74, 056706 (2006).

    Article  ADS  Google Scholar 

  11. Bouyer, V. et al. Shock-to-detonation transition of nitromethane: Time-resolved emission spectroscopy measurements. Combust. Flame 144, 139–150 (2006).

    Article  Google Scholar 

  12. Strachan, A., van Duin, A. C. T., Chakraborty, D., Dasgupta, S. & Goddard, W. A. Shock waves in high-energy materials: The initial chemical events in nitramine rdx. Phys. Rev. Lett. 91, 098301 (2003).

    Article  ADS  Google Scholar 

  13. Kress, J. D., Bickham, S. R., Collins, L. A., Holian, B. L. & Goedecker, S. Tight-binding molecular dynamics of shock waves in methane. Phys. Rev. Lett. 83, 3896–3899 (1999).

    Article  ADS  Google Scholar 

  14. Gygi, F. & Galli, G. Electronic excitations and the compressibility of deuterium. Phys. Rev. B 65, 220102(R) (2002).

    Article  ADS  Google Scholar 

  15. Manaa, M. R., Reed, E. J., Fried, L. E., Galli, G. & Gygi, F. Early chemistry of hot and dense nitromethane: Molecular dynamics simulations. J. Chem. Phys. 120, 10146–10153 (2004).

    Article  Google Scholar 

  16. Margetis, D., Kaxiras, E., Elstner, M., Frauenheim, T. & Manaa, M. R. Electronic structure of solid nitromethane: Effects of high pressure and molecular vacancies. J. Chem. Phys. 117, 788–799 (2002).

    Article  ADS  Google Scholar 

  17. Lysne, P. C. & Hardesty, D. R. Fundamental equation of state of liquid nitromethane to 100 kbar. J. Chem. Phys. 59, 6512–6523 (1973).

    Article  ADS  Google Scholar 

  18. Engelke, R., Sheffield, S. A., Stacy, H. L. & Quintana, J. P. Reduction of detonating liquid nitromethane’s chemical reaction-zone length by chemical sensitization. Phys. Fluids 17, 096102 (2005).

    Article  ADS  Google Scholar 

  19. Zeldovich, Ya. B. On the theory of propagation of detonation in gaseous systems. Zh. Eksp. Teor. Fiz. 10, 542–568 (1940).

    Google Scholar 

  20. von Neumann, J. in John von Neumann, Collected Works Vol. 6 (ed. Taub, A. J.) (Macmillan, New York, 1963).

    Google Scholar 

  21. Doering, W. On detonation processes in gases. Ann. Phys. 43, 421–436 (1943).

    Article  Google Scholar 

  22. Brenner, D. W., Robertson, D. H., Elert, M. L. & White, C. T. Detonations at nanometer resolution using molecular-dynamics. Phys. Rev. Lett. 70, 2174–2177 (1993).

    Article  ADS  Google Scholar 

  23. Blais, N. C., Engelke, R. & Sheffield, S. A. Mass spectroscopic study of the chemical reaction zone in detonating liquid nitromethane. J. Phys. Chem. A 101, 8285–8295 (1997).

    Article  Google Scholar 

  24. Sheffiield, S. A. et al. Particle velocity measurements of the reaction zone in nitromethane. Research Report LA-UR-02-4331 (Los Alamos National Laboratory, 2002).

    Google Scholar 

  25. Mott, N. F. Metal-Insulator Transitions (Taylor and Francis, Bristol, 1990).

    Book  Google Scholar 

  26. Dong, J. & Drabold, D. A. Atomistic structure of band-tail states in amorphous silicon. Phys. Rev. Lett. 80, 1928–1931 (1998).

    Article  ADS  Google Scholar 

  27. Ashwin, S. S., Waghmare, U. V. & Sastry, S. Metal-to-semimetal transition in supercooled liquid silicon. Phys. Rev. Lett. 92, 175701 (2004).

    Article  ADS  Google Scholar 

  28. Mott, N. F. The basis of the electron theory of metals, with special reference to the transition metals. Proc. Phys. Soc. A 62, 416–422 (1949).

    Article  ADS  Google Scholar 

  29. Edwards, P. P. & Sienko, M. J. Universality aspects of metal-nonmetal transition in condensed media. Phys. Rev. B 17, 2575–2581 (1978).

    Article  ADS  Google Scholar 

  30. Anderson, P. W. Absence of diffusion in certain random lattices. Phys. Rev. 109, 1492–1505 (1958).

    Article  ADS  Google Scholar 

  31. Drabold, D. A. Anderson transition and thermal effects on electron states in amorphous silicon. J. Non-cryst. Solids 266, 211–217 (2000).

    Article  ADS  Google Scholar 

  32. Gilev, S. D. & Trubachev, A. M. High electrical conductivity of trotyl detonation products. Tech. Phys. 46, 1185–1189 (2001).

    Article  Google Scholar 

  33. Trevino, S. F., Prince, E. & Hubbard, C. R. Refinement of the structure of solid nitromethane. J. Chem. Phys. 73, 2996–3000 (1980).

    Article  ADS  Google Scholar 

  34. Kroes, G. J., Gross, A., Baerends, E. J., Scheffler, M. & McCormack, D. A. Quantum theory of dissociative chemisorption on metal surfaces. Acc. Chem. Res. 35, 193–200 (2002).

    Article  Google Scholar 

  35. Alfe, D., Gillan, M. J. & Price, G. D. The melting curve of iron at the pressures of the earth’s core from ab initio calculations. Nature 401, 462–464 (1999).

    Article  ADS  Google Scholar 

  36. Baroni, S., de Gironcoli, S. & Corso, A. D. Phonons and related crystal properties from density-functional perturbation theory. Rev. Mod. Phys. 73, 515–562 (2001).

    Article  ADS  Google Scholar 

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Acknowledgements

This work was carried out in part under the auspices of the US Department of Energy by the University of California, Lawrence Livermore National Laboratory (LLNL), under contract number W-7405-Eng-48. Project 06-SI-005 was funded by the Laboratory Directed Research and Development Program at LLNL.

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Contributions to this work: E.J.R., code development, simulations, data analysis; M.R.M., data analysis; L.E.F., data analysis, code development; K.G., code development; J.D.J., data analysis.

Corresponding author

Correspondence to Evan J. Reed.

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Reed, E., Riad Manaa, M., Fried, L. et al. A transient semimetallic layer in detonating nitromethane. Nature Phys 4, 72–76 (2008). https://doi.org/10.1038/nphys806

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