Characteristics of energy exchange between inter- and intramolecular degrees of freedom in crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) with implications for coarse-grained simulations of shock waves in polyatomic molecular crystals

Kroonblawd, Matthew P.; Sewell, Thomas D.; Maillet, Jean‐Bernard

doi:10.1063/1.4941332

Cited by 36 publications

(43 citation statements)

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“…Based on a quantum chemistry calculation of the vibrational frequencies for an isolated TATB molecule, Kroonblawd et al . calculated the temperature dependence of the specific heat per molecule, neglecting the three‐apiece local translations and rotations of/about the molecular center of mass at a lattice site, and modeled it as a sum to two Einstein oscillators. Under the reasonable assumption that these six ‘external oscillators’ in the crystal would be classically populated ( i. e ., in the high‐temperature limit of quantum mechanics) even at very low temperatures, the final form used here for the temperature‐dependent specific heat of the crystal is:

true C_{v} ((), T) = A_{1} {((), \frac{θ_{1}}{normalT})}^{2} \frac{e^{- \frac{θ_{1}}{normalT}}}{{({normale}^{- \frac{θ_{1}}{T}} - 1)}^{2}} + A_{2} {((), \frac{θ_{2}}{normalT})}^{2} \frac{e^{- \frac{θ_{2}}{normalT}}}{{({normale}^{- \frac{θ_{2}}{T}} - 1)}^{2}} + B

…”

Section: Methodsmentioning

confidence: 99%

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Tandem Molecular Dynamics and Continuum Studies of Shock‐Induced Pore Collapse in TATB

Zhao

Lee

Sewell

et al. 2020

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All‐atom molecular dynamics (MD) and Eulerian continuum simulations, performed using the LAMMPS and SCIMITAR3D codes, respectively, were used to study thermo‐mechanical aspects of the shock‐induced collapse of an initially cylindrical 50 nm diameter pore in single crystals of 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB). Three impact speeds, 0.5 km s−1, 1.0 km s−1 and 2.0 km s−1, were used to generate the shocks. These impact conditions are expected to yield collapse mechanisms ranging from predominantly visco‐plastic to hydrodynamic. For the MD studies, three crystal orientations (relative to shock‐propagation direction) were examined that span the limiting cases with respect to the crystalline anisotropy in TATB. An isotropic constitutive model was used for the continuum simulations, thus crystal anisotropy is absent. The evolution of spatiotemporally resolved quantities during collapse is reported including local pressure, temperature, pore size and shape, and material flow. Multiple models for the melting curve and specific heat were studied. Within the isotropic elastic/perfectly plastic continuum framework and for the range of impact conditions studied, the specific heat and melting curve sub‐models are shown to have modest effects on the continuum hotspot predictions in the present inert calculation. Treating the MD predictions as ‘ground truth’, albeit with a classical rather than quantum‐like heat capacity, it is clear that – at a minimum – an extension of the constitutive model to account for crystal plasticity and anisotropic strength will be required for a high‐fidelity continuum description.

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true C_{v} ((), T) = A_{1} {((), \frac{θ_{1}}{normalT})}^{2} \frac{e^{- \frac{θ_{1}}{normalT}}}{{({normale}^{- \frac{θ_{1}}{T}} - 1)}^{2}} + A_{2} {((), \frac{θ_{2}}{normalT})}^{2} \frac{e^{- \frac{θ_{2}}{normalT}}}{{({normale}^{- \frac{θ_{2}}{T}} - 1)}^{2}} + B

…”

Section: Methodsmentioning

confidence: 99%

“…The crystal is triclinic with two molecules per unit cell. The structure of the crystal is strongly anisotropic and this is reflected in pronounced anisotropy for many of the thermal [39][40][41][42][43][44][45][46][47][48][49][50], mechanical [51][52][53][54][55][56][57][58][59][60], and optical properties [61].…”

Section: Introductionmentioning

confidence: 99%

Tandem Molecular Dynamics and Continuum Studies of Shock‐Induced Pore Collapse in TATB

Zhao

Lee

Sewell

et al. 2020

Propellants Explo Pyrotec

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“…TATB crystals tacking-fault energiesw ere also determined [25] using the HB-FF;t he exceptionally low barrier to slid-ing of the planar molecularl ayers was associated [7] with the formation of subtle dynamic structural transitions at (300 K, 0.0 GPa). Simulations of velocityp erturbation relaxation based on the HB-FF werer ecently used to calibrate the dissipative and stochastic parameters in am esoscale rigid-molecule dissipativep article dynamics (DPD) model for TATB [17].…”

Section: Tatb Force Fieldsmentioning

confidence: 99%

“…

1IntroductionCharacterizationo fe nergy transport processes in molecular materials usinga ll-atom molecular dynamics( MD) simulations provides anecessaryand physical basis for the prediction and understanding of experimentally undetermined properties [1][2][3][4][5][6][7],m any of whicha re needed for the parameterization of the kinds of continuum-based mesoscale engineeringm odels widely used to simulate energetic materials [8][9][10][11][12][13][14][15]. Accurate predictionsf or anisotropic bulk material properties such as the thermal conductivity and rate coefficientsf or energyt ransfer processes are necessary if parameterized models are to yield reliable predictions for dynamic processes such as shock loading [9][10][11][12][14][15][16][17][18],h ot spot formation and relaxation [9-12, 14, 15, 19],a nd initiation of chemistry [11,14,19].R ecentM D-based predictions for the thermal conductivity of the insensitivem olecular crystalline explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) revealed significanta nisotropy for energy transport at T = 300 Ka nd P = 0.0 GPa [6,7]. ( Here and for all subsequent instances, pressures reported as 0.0 GPa formally correspond to 1atm, which is 0.0 GPa within the precision of our calculations.)

…”

mentioning

confidence: 99%

Predicted Anisotropic Thermal Conductivity for Crystalline 1,3,5‐Triamino‐2,4,6‐trinitobenzene (TATB): Temperature and Pressure Dependence and Sensitivity to Intramolecular Force Field Terms

Kroonblawd

Sewell

2015

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[a] 1IntroductionCharacterizationo fe nergy transport processes in molecular materials usinga ll-atom molecular dynamics( MD) simulations provides anecessaryand physical basis for the prediction and understanding of experimentally undetermined properties [1][2][3][4][5][6][7],m any of whicha re needed for the parameterization of the kinds of continuum-based mesoscale engineeringm odels widely used to simulate energetic materials [8][9][10][11][12][13][14][15]. Accurate predictionsf or anisotropic bulk material properties such as the thermal conductivity and rate coefficientsf or energyt ransfer processes are necessary if parameterized models are to yield reliable predictions for dynamic processes such as shock loading [9][10][11][12][14][15][16][17][18],h ot spot formation and relaxation [9-12, 14, 15, 19],a nd initiation of chemistry [11,14,19].R ecentM D-based predictions for the thermal conductivity of the insensitivem olecular crystalline explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) revealed significanta nisotropy for energy transport at T = 300 Ka nd P = 0.0 GPa [6,7].( Here and for all subsequent instances, pressures reported as 0.0 GPa formally correspond to 1atm, which is 0.0 GPa within the precision of our calculations.) Many other thermomechanical properties of TATB crystala lso exhibit significant anisotropy [20][21][22][23][24][25][26]. Anisotropy in TATB crystal physical properties is thought to be ac onsequence of the crystal packings tructure, which is triclinic and exhibits al ayered structure, wherein nearly planar TATB molecules form planar single-molecule-thick Abstract:T he anisotropic thermal conductivity of the layered molecular crystal 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), an insensitive secondary high explosive, is determined using classicalm olecular dynamics on the P = 0.0 GPa isobar for temperatures 200 K T 700 Ka nd on the T = 300 Ki sotherm for pressures0 .0 GPa P 2.5 GPa. Sensitivity of the predicted( 300 K, 0.0 GPa) conductivity to intramolecular terms in the forcef ield is investigated.T wo conduction directions are considered, one nominally within and the other exactlyp erpendicular to the stackedp lanar single-molecule-thick layers comprising the TATB crystal. The thermal conductivity l(T,P)a long both directionsi s foundt od ecrease approximately as l / 1/T with increasing temperature and increase approximately linearly l / T with increasingp ressure. The temperature dependence is found to be highly anisotropic with nearly twice as large ar eduction in absolutec onductivity within the molecularl ayers (Dl = À0.67 Wm À1 K À1)c ompared to betweent hem (Dl = À0.35 Wm À1 K À1). Anisotropy in the conductivity is predicted to decrease with increasing temperature;t he P = 0.0 GPa conductivity is 68 %g reater within the layers than betweent hem at 200 K, but only 49 %g reater at 700 K. The pressure dependence is also anisotropic, with a5 1% and 76 %i ncrease in conductivity within and between the layers, respectively.P redictedv alues for the conductivity are found t...

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“…For these reasons, the numerical modeling of TATB crystal plays an essential part in studying its macroscopic behavior. For example, Mathew et al 6 and Kroonblawd et al 7 studied through molecular dynamics (MD) simulations its elastic− plastic response under displacement-controlled nanoindenta- tions and under shock. They reported that some studies 8 have suggested the existence of high defect density in grown crystals of TATB and subtle structural phase transitions under hydrostatic compression.…”

Section: Introductionmentioning

confidence: 99%

Dislocation Core Structure at Finite Temperature Inferred by Molecular Dynamics Simulations for 1,3,5-Triamino-2,4,6-trinitrobenzene Single Crystal

2017

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. ABSTRACT: The dislocation core structures and elastic properties of the insensitive energetic molecular crystal 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) are investigated as a function of pressure and temperature. A new method is proposed to compute the generalized stacking fault surfaces (noted γ-surfaces) and the complete second-order elastic tensor at finite temperature through molecular dynamics (MD) simulations. The energy landscapes in the two glide planes are shown to be similar between 0 and 300 K, thus leading to almost no modification on the dislocation evolution. A spreading of the dislocation cores over a hundred Burgers vectors is observed along the [100] and [010] directions for the edge and screw dislocations at 0 and 300 K, showing that dislocations should exhibit a very low friction for these glide systems at ambient pressure. For pressures varying between 0 and 10 GPa, the γ-surfaces' energy barriers that drive the width of partial dislocations follow the increase of shear elastic constants within the considered glide planes, thus limiting the changes of the dislocation core structure.

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Characteristics of energy exchange between inter- and intramolecular degrees of freedom in crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) with implications for coarse-grained simulations of shock waves in polyatomic molecular crystals

Cited by 36 publications

References 36 publications

Tandem Molecular Dynamics and Continuum Studies of Shock‐Induced Pore Collapse in TATB

Tandem Molecular Dynamics and Continuum Studies of Shock‐Induced Pore Collapse in TATB

Predicted Anisotropic Thermal Conductivity for Crystalline 1,3,5‐Triamino‐2,4,6‐trinitobenzene (TATB): Temperature and Pressure Dependence and Sensitivity to Intramolecular Force Field Terms

Dislocation Core Structure at Finite Temperature Inferred by Molecular Dynamics Simulations for 1,3,5-Triamino-2,4,6-trinitrobenzene Single Crystal

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