163. The crystal structure of pentaerythritol tetranitrate

Booth, Andrew; Llewellyn, F. J.

doi:10.1039/jr9470000837

Cited by 54 publications

(36 citation statements)

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“…4,40 Experimental and DFT calculations also predicted that the PETN molecule has S 4 symmetry in the crystalline phase under ambient conditions. 13,14 PETN has been found experimentally to have three crystalline phases 5,40,41 where the most stable PETN-I has crystal symmetry P42 1 c with two formula units per unit cell. 41 The crystal structure data for Si-PETN are unavailable experimentally due to its extreme instability.…”

Section: Reactive Molecular Dynamics Simulationsmentioning

confidence: 99%

“…13,14 PETN has been found experimentally to have three crystalline phases 5,40,41 where the most stable PETN-I has crystal symmetry P42 1 c with two formula units per unit cell. 41 The crystal structure data for Si-PETN are unavailable experimentally due to its extreme instability. By replacing the central carbon atom of PETN by silicon, Lin et al 21 relaxed three different types of Si-PETN crystal structures by DFT calculations and found that the most stable structure is Si-PETN-I (P42 1 c space group, S 4 molecule symmetry).…”

Section: Reactive Molecular Dynamics Simulationsmentioning

confidence: 99%

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ReaxFF reactive molecular dynamics on silicon pentaerythritol tetranitrate crystal validates the mechanism for the colossal sensitivity

Zhou

Liu

Goddard

et al. 2014

Phys. Chem. Chem. Phys.

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Recently quantum mechanical (QM) calculations on a single Si-PETN (silicon-pentaerythritol tetranitrate) molecule were used to explain its colossal sensitivity observed experimentally in terms of a unique Liu carbon-silyl nitro-ester rearrangement (R 3 Si-CH 2 -O-R 2 -R 3 Si-O-CH 2 -R 2 ). In this paper we expanded the study of Si-PETN from a single molecule to a bulk system by extending the ReaxFF reactive force field to describe similar Si-C-H-O-N systems with parameters optimized to reproduce QM results. The reaction mechanisms and kinetics of thermal decomposition of solid Si-PETN were investigated using ReaxFF reactive molecular dynamics (ReaxFF-RMD) simulations at various temperatures to explore the origin of the high sensitivity. We find that at lower temperatures, the decomposition of Si-PETN is initiated by the Liu carbon-silyl nitro-ester rearrangement forming Si-O bonds which is not observed in PETN. As the reaction proceeds, the exothermicity of Si-O bond formation promotes the onset of NO 2 formation from N-OC bond cleavage which does not occur in PETN. At higher temperatures PETN starts to react by the usual mechanisms of NO 2 dissociation and HONO elimination; however, Si-PETN remains far more reactive. These results validate the predictions from QM that the significantly increased sensitivity of Si-PETN arises from a unimolecular process involving the unusual Liu rearrangement but not from multi-molecular collisions. It is the very low energy barrier and the high exothermicity of the Si-O bond formation providing energy early in the decomposition process that is responsible.

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Section: Reactive Molecular Dynamics Simulationsmentioning

confidence: 99%

Section: Reactive Molecular Dynamics Simulationsmentioning

confidence: 99%

ReaxFF reactive molecular dynamics on silicon pentaerythritol tetranitrate crystal validates the mechanism for the colossal sensitivity

Zhou

Liu

Goddard

et al. 2014

Phys. Chem. Chem. Phys.

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“…13 A tetragonal lattice with space-group symmetry P42 1 c was determined, with two C͑CH 2 ONO 2 ͒ 4 molecules ͑58 atoms͒ per unit cell. 12 Importantly, it was noted that weak van der Waals forces play a vital role in the intermolecular interactions. 12 We denote the PETN-I polymorph as PETN, but a second polymorph, PETN-II, has been reported at high temperature 14 and a third polymorph, PETN-III has recently been reported near 6 GPa.…”

Section: Introductionmentioning

confidence: 99%

“…PETN is an exemplary EM for these calculations, as its anomalous anisotropic shock-initiation behavior [1][2][3] can be probed at the atomic scale. The crystal structure of PETN was studied experimentally via x-ray diffraction by Booth and Llewellyn, 12 whose data were later revised by Trotter. 13 A tetragonal lattice with space-group symmetry P42 1 c was determined, with two C͑CH 2 ONO 2 ͒ 4 molecules ͑58 atoms͒ per unit cell.…”

Section: Introductionmentioning

confidence: 99%

First-principles investigation of anisotropic constitutive relationships in pentaerythritol tetranitrate

et al. 2008

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First-principles density functional theory ͑DFT͒ calculations have been used to obtain the constitutive relationships of pentaerythritol tetranitrate ͑PETN-I͒, a crystalline energetic material. The isotropic equation of state ͑EOS͒ for hydrostatic compression has been extended to include uniaxial compressions in the ͗100͘, ͗010͘, ͗001͘, ͗110͘, ͗101͘, ͗011͘, and ͗111͘ crystallographic directions up to a compression ratio of V / V 0 = 0.70. DFT predicts equilibrium properties such as lattice parameters and elastic constants, as well as the hydrostatic EOS, in agreement with available experimental data. Our results show a substantial anisotropy of various properties of PETN-I upon uniaxial compression. To characterize the anisotropic traits of PETN, different physical properties of the uniaxially compressed crystal such as the energy per atom, band gap, and stress tensor have been evaluated as a function of compression ratio. The maximum shear stresses were calculated and examined for a correlation with the anisotropy in shock-initiation sensitivity.

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“…Only when temperature and ZPE effects are included is good agreement with experiment obtained. For instance, the unit cell volume for PETN-I determined by experiment [9] at 300 K is 589.5 Å 3 , and is predicted to be 590.7 Å 3 by DFT+vdW+T. Likewise, NM at 4.2 K was determined [10] to be 275.3 Å 3 , but was also predicted to be 275.3 Å 3 by DFT+vdW+T.…”

Section: Resultsmentioning

confidence: 99%

First-principles thermodynamics of energetic materials

Landerville¹,

Conroy²,

Lin³

et al. 2012

AIP Conference Proceedings

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Abstract.Using density functional theory with empirical van der Waals corrections, cold pressure curves were calculated and combined with the quasi-harmonic approximation to study thermodynamical properties of several energetic molecular solids. Vibration spectra at each compression were calculated and used for including temperature and zero-point energy contributions to the free energy. Equilibrium properties at temperatures of experiments, as well as hydrostatic equations of state, specific heat capacities, and coefficients of thermal expansion, were obtained and compared to experiment.

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163. The crystal structure of pentaerythritol tetranitrate

Cited by 54 publications

References 0 publications

ReaxFF reactive molecular dynamics on silicon pentaerythritol tetranitrate crystal validates the mechanism for the colossal sensitivity

ReaxFF reactive molecular dynamics on silicon pentaerythritol tetranitrate crystal validates the mechanism for the colossal sensitivity

First-principles investigation of anisotropic constitutive relationships in pentaerythritol tetranitrate

First-principles thermodynamics of energetic materials

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