1
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Atceken N, Hemingway J, Bull CL, Liu X, Michalchuk AAL, Konar S, Morrison CA, Pulham CR. High-pressure structural studies and pressure-induced sensitisation of 3,4,5-trinitro-1 H-pyrazole. Phys Chem Chem Phys 2023; 25:31646-31654. [PMID: 37986575 DOI: 10.1039/d3cp04526a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Herein we report the first high-pressure study of the energetic material 3,4,5-trinitro-1H-pyrazole (3,4,5-TNP) using neutron powder diffraction and single-crystal X-ray diffraction. A new high-pressure phase, termed Form II, was first identified through a substantial change in the neutron powder diffraction patterns recorded over the range 4.6-5.3 GPa, and was characterised further by compression of a single crystal to 5.3 GPa in a diamond-anvil cell using X-ray diffraction. 3,4,5-TNP was found to be sensitive to initiation under pressure, as demonstrated by its unexpected and violent decomposition at elevated pressures in successive powder diffraction experiments. Initiation coincided with the sluggish phase transition from Form I to Form II. Using a vibrational up-pumping model, its increased sensitivity under pressure can be explained by pressure-induced mode hardening. These findings have potential implications for the safe handling of 3,4,5-TNP, on the basis that shock- or pressure-loading may lead to significantly increased sensitivity to initiation.
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Affiliation(s)
- Nurunnisa Atceken
- Department of Materials Science and Engineering, İzmir Institute of Technology, Urla, 35430, İzmir, Turkey
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, The University of Edinburgh, King's Buildings, David Brewster Road, Edinburgh EH9 3FJ, UK.
| | - Jack Hemingway
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, The University of Edinburgh, King's Buildings, David Brewster Road, Edinburgh EH9 3FJ, UK.
| | - Craig L Bull
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, The University of Edinburgh, King's Buildings, David Brewster Road, Edinburgh EH9 3FJ, UK.
- ISIS Neutron and Muon Facility, STFC Rutherford Appleton Laboratory, Harwell, Oxford, Didcot, Oxfordshire OX11 0QX, UK
| | - Xiaojiao Liu
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, The University of Edinburgh, King's Buildings, David Brewster Road, Edinburgh EH9 3FJ, UK.
| | - Adam A L Michalchuk
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Sumit Konar
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, The University of Edinburgh, King's Buildings, David Brewster Road, Edinburgh EH9 3FJ, UK.
- Joseph Banks Laboratories, School of Chemistry, University of Lincoln, Lincoln, UK
| | - Carole A Morrison
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, The University of Edinburgh, King's Buildings, David Brewster Road, Edinburgh EH9 3FJ, UK.
| | - Colin R Pulham
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, The University of Edinburgh, King's Buildings, David Brewster Road, Edinburgh EH9 3FJ, UK.
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2
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O’Connor D, Bier I, Tom R, Hiszpanski AM, Steele BA, Marom N. Ab Initio Crystal Structure Prediction of the Energetic Materials LLM-105, RDX, and HMX. CRYSTAL GROWTH & DESIGN 2023; 23:6275-6289. [PMID: 38173900 PMCID: PMC10763925 DOI: 10.1021/acs.cgd.3c00027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 08/02/2023] [Indexed: 01/05/2024]
Abstract
Crystal structure prediction (CSP) is performed for the energetic materials (EMs) LLM-105 and α-RDX, as well as the α and β conformational polymorphs of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), using the genetic algorithm (GA) code, GAtor, and its associated random structure generator, Genarris. Genarris and GAtor successfully generate the experimental structures of all targets. GAtor's symmetric crossover scheme, where the space group symmetries of parent structures are treated as genes inherited by offspring, is found to be particularly effective. However, conducting several GA runs with different settings is still important for achieving diverse samplings of the potential energy surface. For LLM-105 and α-RDX, the experimental structure is ranked as the most stable, with all of the dispersion-inclusive density functional theory (DFT) methods used here. For HMX, the α form was persistently ranked as more stable than the β form, in contrast to experimental observations, even when correcting for vibrational contributions and thermal expansion. This may be attributed to insufficient accuracy of dispersion-inclusive DFT methods or to kinetic effects not considered here. In general, the ranking of some putative structures is found to be sensitive to the choice of the DFT functional and the dispersion method. For LLM-105, GAtor generates a putative structure with a layered packing motif, which is desirable thanks to its correlation with low sensitivity. Our results demonstrate that CSP is a useful tool for studying the ubiquitous polymorphism of EMs and shows promise of becoming an integral part of the EM development pipeline.
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Affiliation(s)
- Dana O’Connor
- Department
of Materials Science and Engineering, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Imanuel Bier
- Department
of Materials Science and Engineering, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Rithwik Tom
- Department
of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Anna M. Hiszpanski
- Materials
Science Division, Lawrence Livermore National
Laboratory, Livermore, California 94550, United States
| | - Brad A. Steele
- Materials
Science Division, Lawrence Livermore National
Laboratory, Livermore, California 94550, United States
| | - Noa Marom
- Department
of Materials Science and Engineering, Carnegie
Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Department
of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Department
of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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3
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Price AJA, Otero-de-la-Roza A, Johnson ER. XDM-corrected hybrid DFT with numerical atomic orbitals predicts molecular crystal lattice energies with unprecedented accuracy. Chem Sci 2023; 14:1252-1262. [PMID: 36756332 PMCID: PMC9891363 DOI: 10.1039/d2sc05997e] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Molecular crystals are important for many applications, including energetic materials, organic semiconductors, and the development and commercialization of pharmaceuticals. The exchange-hole dipole moment (XDM) dispersion model has shown good performance in the calculation of relative and absolute lattice energies of molecular crystals, although it has traditionally been applied in combination with plane-wave/pseudopotential approaches. This has limited XDM to use with semilocal functional approximations, which suffer from delocalization error and poor quality conformational energies, and to systems with a few hundreds of atoms at most due to unfavorable scaling. In this work, we combine XDM with numerical atomic orbitals, which enable the efficient use of XDM-corrected hybrid functionals for molecular crystals. We test the new XDM-corrected functionals for their ability to predict the lattice energies of molecular crystals for the X23 set and 13 ice phases, the latter being a particularly stringent test. A composite approach using a XDM-corrected, 25% hybrid functional based on B86bPBE achieves a mean absolute error of 0.48 kcal mol-1 per molecule for the X23 set and 0.19 kcal mol-1 for the total lattice energies of the ice phases, compared to recent diffusion Monte-Carlo data. These results make the new XDM-corrected hybrids not only far more computationally efficient than previous XDM implementations, but also the most accurate density-functional methods for molecular crystal lattice energies to date.
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Affiliation(s)
- Alastair J. A. Price
- Department of Chemistry, Dalhousie University6274 Coburg RdHalifaxB3H 4R2Nova ScotiaCanada
| | - Alberto Otero-de-la-Roza
- Departamento de Química Física y Analítica and MALTA-Consolider Team, Facultad de Química, Universidad de Oviedo Oviedo 33006 Spain
| | - Erin R. Johnson
- Department of Chemistry, Dalhousie University6274 Coburg RdHalifaxB3H 4R2Nova ScotiaCanada
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4
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Xu WS, Zhu J, Hu YF, Ji GF. Molecular Dynamics Study on the Reaction of RDX Molecule with Si Substrate. ACS OMEGA 2023; 8:4270-4277. [PMID: 36743027 PMCID: PMC9893248 DOI: 10.1021/acsomega.2c07512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/11/2023] [Indexed: 06/18/2023]
Abstract
RDX is widely used in various explosion situations, and there are many studies on its detonation performance, safety, preparation, etc. Research on preparation of β-RDX is mainly conducted by experiments. In recent years, part of the research points to the use of substrate as a medium to produce β-RDX faster. Based on this guidance, our work aims to theoretically solve the physical and chemical processes that RDX may experience in the production process through numerical simulation. In this work, molecular dynamics simulation is set up for the interaction between RDX and a Si clean surface and a Si hydroxyl saturated surface separately, and a higher precision simulation is set up to verify the reliability of the results. NCI analysis is also used to guess the possible phase transition mechanism in the simulation results. In the simulation process, a 7 × 7 Si clean surface, a 3 × 3 Si clean surface, and a 7 × 7 Si-OH surface are set, and each surface adsorbs one α-RDX. The semiempirical Gfn1-xtb method is used for the 7 × 7 surface, and the DFT method is used for the 3 × 3 surface. The calculation results confirmed by high-precision results show that RDX molecules will react with the dangling bonds on the Si surface. Three conformations of RDX were found on the hydroxyl saturated surface of Si. The isosurface generated by the NCI method is used to analyze the reasons for the formation of these conformations.
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Affiliation(s)
- Wei-Sen Xu
- Department
of Engineering Mechanics, University of
Science and Technology of China, Hefei 230026, Anhui, P. R. China
- Institute
of Fluid Physics, China Academy of Engineering
Physics, Mianyang 621900, P. R. China
| | - Jing Zhu
- Institute
of Fluid Physics, China Academy of Engineering
Physics, Mianyang 621900, P. R. China
| | - Yan-Fei Hu
- Department
of Applied Physics, Chengdu University of
Technology, Chengdu 610059, P. R. China
| | - Guang-Fu Ji
- Institute
of Fluid Physics, China Academy of Engineering
Physics, Mianyang 621900, P. R. China
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5
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Feng S, Guo F, Yuan C, Cheng X, Wang Y, Zhang H, Chen J, Su L. Effect of neutron irradiation on structure and decomposition of α-RDX: a ReaxFF molecular dynamics study. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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6
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Hu Y, Zhang J, Luo P. Solvent effects on the original molecular recovery from the solvated solute monomers of cyclic nitramine explosives. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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7
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Kroonblawd MP, Springer HK. Predicted Melt Curve and Liquid Shear Viscosity of RDX up to 30 GPa. PROPELLANTS EXPLOSIVES PYROTECHNICS 2022. [DOI: 10.1002/prep.202100328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Matthew P. Kroonblawd
- Energetic Materials Center Lawrence Livermore National Laboratory 700 East Avenue Livermore CA 94550 USA
| | - H. Keo Springer
- Energetic Materials Center Lawrence Livermore National Laboratory 700 East Avenue Livermore CA 94550 USA
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8
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Wang C, Zhang C, Xue X. Pressure and Polymorph Dependent Thermal Decomposition Mechanism of Molecular Materials: A Case of 1,3,5,-Trinitro-1,3,5,-triazine. J Phys Chem A 2022; 126:463-472. [PMID: 35061375 DOI: 10.1021/acs.jpca.1c08171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
1,3,5,-Trinitro-1,3,5,-triazine (RDX) serves as an important energetic material and is widely used as various solid propellants and explosives. Understanding the thermal decomposition behaviors of various polymorphs of RDX at high pressure and high temperature is significantly important for safe storage and handling. The present work reveals the early thermal decay mechanisms of two polymorphs (α- and ε-forms) of RDX at high pressure and high temperature by ReaxFF reactive molecular dynamic simulations and climbing image nudged elastic band (CI-NEB) static calculations. It is found that the thermal decomposition rate has positive and negative effects on the pressure for α- and ε-RDX, respectively. This difference originates from the difference of pressure effect on the intermolecular H transfer of the two polymorphs, as we confirm that the bimolecular H transfer rather than the NO2 partition initiates the decay with a significantly lower energy barrier therein. This finding may be beneficial to understand the pressure and polymorph dependent effect on the decay of RDX and to develop a kinetic model for the combustion of solid RDX.
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Affiliation(s)
- Chaoyu Wang
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), P.O. Box 919-311, Mianyang, Sichuan 621999, China.,Department of Materials Science and the Advanced Coatings Research Center of the China Educational Ministry, Fudan University, Shanghai, 200433, China
| | - Chaoyang Zhang
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), P.O. Box 919-311, Mianyang, Sichuan 621999, China.,Beijing Computational Science Research Center, Beijing, 100048, China
| | - Xianggui Xue
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), P.O. Box 919-311, Mianyang, Sichuan 621999, China
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9
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Low Temperature and High-Pressure Study of Bending L-Leucinium Hydrogen Maleate Crystals. CRYSTALS 2021. [DOI: 10.3390/cryst11121575] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The polymorphism of molecular crystals is a well-known phenomenon, resulting in modifications of physicochemical properties of solid phases. Low temperatures and high pressures are widely used to find phase transitions and quench new solid forms. In this study, L-Leucinium hydrogen maleate (LLHM), the first molecular crystal that preserves its anomalous plasticity at cryogenic temperatures, is studied at extreme conditions using Raman spectroscopy and optical microscopy. LLHM was cooled down to 11 K without any phase transition, while high pressure impact leads to perceptible changes in crystal structure in the interval of 0.0–1.35 GPa using pentane-isopentane media. Surprisingly, pressure transmitting media (PTM) play a significant role in the behavior of the LLHM system at extreme conditions—we did not find any phase change up to 3.05 GPa using paraffin as PTM. A phase transition of LLHM to amorphous form or solid–solid phase transition(s) that results in crystal fracture is reported at high pressures. LLHM stability at low temperatures suggests an alluring idea to prove LLHM preserves plasticity below 77 K.
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10
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Izvekov S, Rice BM. Bottom-up coarse-grain modeling of plasticity and nanoscale shear bands in α-RDX. J Chem Phys 2021; 155:064503. [PMID: 34391357 DOI: 10.1063/5.0057223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Computationally inexpensive particle-based coarse-grained (CG) models are essential for use in molecular dynamics (MD) simulations of mesoscopically slow cooperative phenomena, such as plastic deformations in solids. Molecular crystals possessing complex symmetry present enormous practical challenges for particle-based coarse-graining at molecularly resolved scales, when each molecule is in a single-site representation, and beyond. Presently, there is no published pairwise non-bonded single-site CG potential that is able to predict the space group and structure of a molecular crystal. In this paper, we present a successful coarse-graining at a molecular level from first principles of an energetic crystal, hexahydro-1,3,5-trinitro-s-triazine (RDX) in the alpha phase, using the force-matching-based multiscale coarse-graining (MSCG/FM) approach. The new MSCG/FM model, which implements an optimal pair decomposition of the crystal Helmholtz free energy potential in molecular center-of-mass coordinates, was obtained by force-matching atomistic MD simulations of liquid, amorphous, and crystalline states and in a wide range of pressures (up to 20 GPa). The MSCG/FM potentials for different pressures underwent top-down optimization to fine-tune the mechanical and thermodynamic properties, followed by consolidation into a transferable density-dependent model referred to as RDX-TC-DD (RDX True-Crystal Density-Dependent). The RDX-TC-DD model predicts accurately the crystal structure of α-RDX at room conditions and reproduces the atomistic reference system under isothermal (300 K) hydrostatic compression up to 20 GPa, in particular, the Pbca symmetry of α-RDX in the elastic regime. The RDX-TC-DD model was then used to simulate the plastic response of uniaxially ([100]) compressed α-RDX resulting in nanoscale shear banding, a key mechanism for plastic deformation and defect-free detonation initiation proposed for many molecular crystalline explosives. Additionally, a comparative analysis of the effect of core-softening of the RDX-TC-DD potential and the degree of molecular rigidity in the all-atom treatment suggests a stress-induced short-range softening of the effective intermolecular interaction as a fundamental cause of plastic instability in α-RDX. The reported RDX-TC-DD model and overall workflow to develop it open up possibilities to perform high quality simulation studies of molecular energetic materials under thermal and mechanical stimuli, including extreme conditions.
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Affiliation(s)
- Sergei Izvekov
- Weapons and Materials Research Directorate, U.S. Army DEVCOM Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, USA
| | - Betsy M Rice
- Weapons and Materials Research Directorate, U.S. Army DEVCOM Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, USA
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11
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Li C, Li H, Zong HH, Huang Y, Gozin M, Sun CQ, Zhang L. Strategies for Achieving Balance between Detonation Performance and Crystal Stability of High-Energy-Density Materials. iScience 2020; 23:100944. [PMID: 32163898 PMCID: PMC7066234 DOI: 10.1016/j.isci.2020.100944] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/18/2020] [Accepted: 02/21/2020] [Indexed: 01/07/2023] Open
Abstract
Performance-stability contradiction of high-energy-density materials (HEDMs) is a long-standing puzzle in the field of chemistry and material science. Bridging the gap that exists between detonation performance of new HEDMs and their stability remains a formidable challenge. Achieving optimal balance between the two contradictory factors is of a significant demand for deep-well oil and gas drilling, space exploration, and other civil and defense applications. Herein, supercomputers and latest quantitative computational strategies were employed and high-throughput quantum calculations were conducted for 67 reported HEDMs. Based on statistical analysis of large amounts of physico-chemical data, in-crystal interspecies interactions were identified to be the one that provokes the performance-stability contradiction of HEDMs. To design new HEDMs with both good detonation performance and high stability, the proposed systematic and comprehensive strategies must be satisfied, which could promote the development of crystal engineering of HEDMs to an era of theory-guided rational design of materials.
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Affiliation(s)
- Chongyang Li
- Key Laboratory of Low-dimensional Materials and Application Technology (Ministry of Education), School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China; CAEP Software Center for High Performance Numerical Simulation, Beijing 100088, China
| | - Hui Li
- Science and Technology on Combustion and Explosion Laboratory, Xi'an Modern Chemistry Research Institute, Xi'an 710065, China; School of Chemistry, Faculty of Exact Science, Tel Aviv University, Tel Aviv 69978, Israel
| | - He-Hou Zong
- Institute of Chemical Materials, China Academy of EngineeringPhysics (CAEP), Mianyang 621900, China
| | - Yongli Huang
- Key Laboratory of Low-dimensional Materials and Application Technology (Ministry of Education), School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China.
| | - Michael Gozin
- School of Chemistry, Faculty of Exact Science, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Chang Q Sun
- EBEAM, Yangtze Normal University, Chongqing 408100, China; NOVITAS, Nanyang Technological University, Singapore 639798, Singapore.
| | - Lei Zhang
- CAEP Software Center for High Performance Numerical Simulation, Beijing 100088, China; Institute of Applied Physics and Computational Mathematics, Beijing 100088, China.
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12
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Liu Y, Xu Y, Sun Q, Lu M. Modification of crystalline energetic salts through polymorphic transition: enhanced crystal density and energy performance. CrystEngComm 2020. [DOI: 10.1039/d0ce00056f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We presented a detailed investigation of polymorphic transition of energetic salts and explored a new path for modifying crystalline energetic salts.
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Affiliation(s)
- Yang Liu
- School of Chemical Engineering
- Nanjing University of Science and Technology
- Nanjing 210094
- China
| | - Yuangang Xu
- School of Chemical Engineering
- Nanjing University of Science and Technology
- Nanjing 210094
- China
| | - Qi Sun
- School of Chemical Engineering
- Nanjing University of Science and Technology
- Nanjing 210094
- China
| | - Ming Lu
- School of Chemical Engineering
- Nanjing University of Science and Technology
- Nanjing 210094
- China
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13
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Xu X, Chen D, Li H, Yan M, Xiong Y, Zhao H, Xu R. Crystal structure evolution of an energetic compound dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate induced by solvents. RSC Adv 2020; 10:11939-11944. [PMID: 35496585 PMCID: PMC9050641 DOI: 10.1039/d0ra01182g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 03/15/2020] [Indexed: 11/22/2022] Open
Abstract
Recently, energetic ionic salts have become a research hotspot due to their attractive properties, such as high density, high heat of formation, and environmental friendliness. Dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) is a typical nitrogen-rich energetic ionic salt, which has broad application prospects. However, the research on the stability and crystal structure evolution of TKX-50 in different solvent systems is insufficient. Herein, we investigated the crystal structure transformations and searched for new solid forms of TKX-50 under different conditions via a solvent induction method. The phase composition of all screened samples was analyzed by powder or single-crystal X-ray diffraction. Three new solid forms of [NH2(CH3)2+][BTO−], [NH2(CH3CH2)2+]2[BTO2−], [NHOH(CH3CCH3)+][BTO−] H2O were obtained from DMAC, DEF and AC/MT, respectively. Furthermore, the energetic properties were evaluated through EXPLO5. Three new solvent compounds obtained by dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate recrystallized from three solvents.![]()
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Affiliation(s)
- Xin Xu
- Institute of Chemical Materials
- China Academy of Engineering Physics
- Mianyang
- China
- College of Environment and Safety Engineering
| | - Dong Chen
- Institute of Chemical Materials
- China Academy of Engineering Physics
- Mianyang
- China
| | - Hongzhen Li
- Institute of Chemical Materials
- China Academy of Engineering Physics
- Mianyang
- China
| | - Mi Yan
- Institute of Chemical Materials
- China Academy of Engineering Physics
- Mianyang
- China
| | - Ying Xiong
- Institute of Chemical Materials
- China Academy of Engineering Physics
- Mianyang
- China
| | - Haixia Zhao
- College of Environment and Safety Engineering
- North University of China
- Taiyuan
- China
| | - Rong Xu
- Institute of Chemical Materials
- China Academy of Engineering Physics
- Mianyang
- China
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14
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15
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Ren J, Chen D, Liu G, Wang K, Fan G, Yu Y, Zhang C, Li H. Crystal structure evolution of the high energetic compound carbonic dihydrazidinium bis[3-(5-nitroimino-1,2,4-triazolate)] induced by solvents. CrystEngComm 2020. [DOI: 10.1039/c9ce01329f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four new solid forms of CBNT including CBNT·2H2O, H2BNT·2DMSO, H2BNT·2H2O and [NH2(CH3)2+]2[BNT2−]·2H2O were successfully obtained from water, DMSO, BL/H2O and DMF/H2O through a solvent induction method.
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Affiliation(s)
- Jianrong Ren
- Institute of Chemical Materials
- China Academy of Engineering Physics (CAEP)
- Mianyang 621900
- China
- College of Environment and Safety Engineering
| | - Dong Chen
- Institute of Chemical Materials
- China Academy of Engineering Physics (CAEP)
- Mianyang 621900
- China
| | - Guangrui Liu
- Institute of Chemical Materials
- China Academy of Engineering Physics (CAEP)
- Mianyang 621900
- China
- College of Environment and Safety Engineering
| | - Kangcai Wang
- Institute of Chemical Materials
- China Academy of Engineering Physics (CAEP)
- Mianyang 621900
- China
| | - Guijuan Fan
- Institute of Chemical Materials
- China Academy of Engineering Physics (CAEP)
- Mianyang 621900
- China
| | - Yanwu Yu
- College of Environment and Safety Engineering
- North University of China
- Taiyuan 030051
- China
| | - Chaoyang Zhang
- Institute of Chemical Materials
- China Academy of Engineering Physics (CAEP)
- Mianyang 621900
- China
| | - Hongzhen Li
- Institute of Chemical Materials
- China Academy of Engineering Physics (CAEP)
- Mianyang 621900
- China
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16
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Sun C, Zhang W, Lü Y, Wang F, Guo W, Zhang T, Yao Y. Trends of the macroscopic behaviors of energetic compounds: insights from first-principles calculations. Phys Chem Chem Phys 2019; 21:24034-24041. [PMID: 31646318 DOI: 10.1039/c9cp05222d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Understanding the structure-property relationships of energetic compounds is challenging. Herein, by including the experimental data, we systematically evaluated the microscopic characteristics of a series of transition metal carbohydrazide perchlorate (TMCP) complexes (MnCP, FeCP, CoCP, NiCP, ZnCP, and CdCP) by first-principles calculations. The calculated properties, i.e., lattice enthalpy, bulk modulus, and electronic structures, were correlated with their thermal decomposition temperatures and impact sensitivities, which indicated that the stability and sensitivity of the TMCP complexes were greatly changed through coordination with different metal ions. The trend was that a large lattice enthalpy indicated a better thermal stability. Complexes with a high impact sensitivity tended to have a smaller bulk modulus and pseudo-gap. The ultra-high impact sensitivity of FeCP may have been related to the unstable spin state with respect to the volume change in the lattice. The calculated bond order and bond dissociation energy did not fully reflect the impact and friction sensitivities in this study. In addition, the combination of crystal properties and local bond information may better describe the sensitivity trend for the TMCP energetic compounds. This analysis can be applied to other energetic compounds and may provide clues for the synthesis and assessment of novel energetic compounds.
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Affiliation(s)
- Chuli Sun
- School of Physics, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing 100081, P. R. China.
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Aina AA, Misquitta AJ, Phipps MJS, Price SL. Charge Distributions of Nitro Groups Within Organic Explosive Crystals: Effects on Sensitivity and Modeling. ACS OMEGA 2019; 4:8614-8625. [PMID: 31459950 PMCID: PMC6648017 DOI: 10.1021/acsomega.9b00648] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/03/2019] [Indexed: 06/10/2023]
Abstract
The charge distribution of NO2 groups within the crystalline polymorphs of energetic materials strongly affects their explosive properties. We use the recently introduced basis-space iterated stockholder atom partitioning of high-quality charge distributions to examine the approximations that can be made in modeling polymorphs and their physical properties, using 1,3,5-trinitroperhydro-1,3,5-triazine, trinitrotoluene, 1-3-5-trinitrobenzene, and hexanitrobenzene as exemplars. The NO2 charge distribution is strongly affected by the neighboring atoms, the rest of the molecules, and also significantly by the NO2 torsion angle within the possible variations found in observed crystal structures. Thus, the proposed correlations between the molecular electrostatic properties, such as trigger-bond potential or maxima in the electrostatic potential, and impact sensitivity will be affected by the changes in conformation that occur on crystallization. We establish the relationship between the NO2 torsion angle and the likelihood of occurrence in observed crystal structures, the conformational energy, and the charge and dipole magnitude on each atom, and how this varies with the neighboring groups. We examine the effect of analytically rotating the atomic multipole moments to model changes in torsion angle and establish that this is a viable approach for crystal structures but is not accurate enough to model the relative lattice energies. This establishes the basis of transferability of the NO2 charge distribution for realistic nonempirical model intermolecular potentials for simulating energetic materials.
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Affiliation(s)
- Alexander A Aina
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
| | - Alston J Misquitta
- School of Physics and Astronomy and the Thomas Young Centre for Theory and Simulation of Materials at Queen Mary, University of London, London E1 4NS, U.K
| | | | - Sarah L Price
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K
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18
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Abstract
There are a large number of materials with mild stiffness, which are not as soft as tissues and not as strong as metals. These semihard materials include energetic materials, molecular crystals, layered materials, and van der Waals crystals. The integrity and mechanical stability are mainly determined by the interactions between instantaneously induced dipoles, the so called London dispersion force or van der Waals force. It is challenging to accurately model the structural and mechanical properties of these semihard materials in the frame of density functional theory where the non-local correlation functionals are not well known. Here, we propose a van der Waals density functional named vdW-DFq to accurately model the density and geometry of semihard materials. Using β -cyclotetramethylene tetranitramine as a prototype, we adjust the enhancement factor of the exchange energy functional with generalized gradient approximations. We find this method to be simple and robust over a wide tuning range when calibrating the functional on-demand with experimental data. With a calibrated value q = 1.05 , the proposed vdW-DFq method shows good performance in predicting the geometries of 11 common energetic material molecular crystals and three typical layered van der Waals crystals. This success could be attributed to the similar electronic charge density gradients, suggesting a wide use in modeling semihard materials. This method could be useful in developing non-empirical density functional theories for semihard and soft materials.
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19
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Liu Y, Shen C, Lu M. Boosting the performance of energetic materials through thermally-induced conformational transition. CrystEngComm 2019. [DOI: 10.1039/c8ce01825a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We presented an effective strategy to improve the performance of energetic materials through thermally-induced conformational transition.
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Affiliation(s)
- Yang Liu
- School of Chemical Engineering
- Nanjing University of Science and Technology
- Nanjing 210094
- China
| | - Cheng Shen
- School of Chemical Engineering
- Nanjing University of Science and Technology
- Nanjing 210094
- China
| | - Ming Lu
- School of Chemical Engineering
- Nanjing University of Science and Technology
- Nanjing 210094
- China
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20
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Abstract
A comprehensive theoretical study of 18 metal azides is reported.
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Affiliation(s)
- Sergey V. Bondarchuk
- Department of Chemistry and Nanomaterials Science
- Bogdan Khmelnitsky Cherkasy National University
- 18031 Cherkasy
- Ukraine
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21
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Bondarchuk SV. Quantification of Impact Sensitivity Based on Solid-State Derived Criteria. J Phys Chem A 2018; 122:5455-5463. [PMID: 29851488 DOI: 10.1021/acs.jpca.8b01743] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sergey V. Bondarchuk
- Department of Chemistry and Nanomaterials Science, Bogdan Khmelnitsky Cherkasy National University, blvd. Shevchenko 81, 18031 Cherkasy, Ukraine
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22
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Thomas LH, Wales C, Wilson CC. Selective preparation of elusive and alternative single component polymorphic solid forms through multi-component crystallisation routes. Chem Commun (Camb) 2018; 52:7372-5. [PMID: 27079688 DOI: 10.1039/c6cc01027j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A transferable, simple, method for producing previously elusive and novel polymorphic forms of important active pharmaceutical ingredients (APIs; paracetamol (acetaminophen), piroxicam and piracetam) is demonstrated. Nitrogen heterocyclic co-molecules are employed to influence the self-assembly crystallisation process in a multi-component environment. Previously unknown solvates have also been synthesised by this method.
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Affiliation(s)
- Lynne H Thomas
- Department of Chemistry, University of Bath, Bath BA2 7AY, UK.
| | - Craig Wales
- Department of Chemistry, University of Bath, Bath BA2 7AY, UK. and School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK
| | - Chick C Wilson
- Department of Chemistry, University of Bath, Bath BA2 7AY, UK. and CMAC, EPSRC Centre for Continuous Manufacturing and Crystallisation, Department of Chemistry, University of Bath, Bath BA2 7AY, UK
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23
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Brady JJ, Argirakis BL, Gordon AD, Lareau RT, Smith BT. Polymorphic Phase Control of RDX-Based Explosives. APPLIED SPECTROSCOPY 2018; 72:28-36. [PMID: 28537423 DOI: 10.1177/0003702817712259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The polymorphic phase of 1,3,5-trinitro-1,3,5-triazine (RDX) was examined as a function of mass loading, solvent, and sample deposition technique. When RDX was deposited at a high mass loading, the vibrational modes in the obtained Raman spectra were indicative of concomitant polymorphism as both the α-RDX and β-RDX phases were present. At low mass loadings, only β-RDX was observed regardless of solvent when using the drop cast crystallization method. However, α-RDX (the thermodynamically stable polymorphic phase observed with visible quantities of the explosive) was observed when RDX deposits were dry transferred. Observation of α-RDX was independent of the initial mass loading or the initial deposition solvent when using the dry transfer methodology. These data indicate that the use of the dry transfer preparation method can be used to successfully prepare RDX-based test articles with the α-RDX phase regardless of the solvent used to initially dissolve the RDX, the initial deposition technique, or the mass loading.
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Affiliation(s)
- John J Brady
- 1 Transportation Security Laboratory, William J. Hughes Technical Center, Atlantic City, NJ, USA
| | - Brittney L Argirakis
- 1 Transportation Security Laboratory, William J. Hughes Technical Center, Atlantic City, NJ, USA
- 2 Penn State University, University Park, PA, USA
| | - Alexander D Gordon
- 1 Transportation Security Laboratory, William J. Hughes Technical Center, Atlantic City, NJ, USA
- 3 Signature Science, LLC, Egg Harbor Township, NJ, USA
| | - Richard T Lareau
- 1 Transportation Security Laboratory, William J. Hughes Technical Center, Atlantic City, NJ, USA
| | - Barry T Smith
- 1 Transportation Security Laboratory, William J. Hughes Technical Center, Atlantic City, NJ, USA
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24
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Gao C, Zhang X, Zhang C, Sui Z, Hou M, Dai R, Wang Z, Zheng X, Zhang Z. Effect of pressure gradient and new phases for 1,3,5-trinitrohexahydro-s-triazine (RDX) under high pressures. Phys Chem Chem Phys 2018; 20:14374-14383. [PMID: 29770413 DOI: 10.1039/c8cp01192c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Herein, pressure-induced phase transitions of RDX up to 50 GPa were systematically studied under different compression conditions.
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Affiliation(s)
- Chan Gao
- Department of Physics
- University of Science and Technology of China
- Hefei
- China
| | - Xueyong Zhang
- Department of Chemistry
- Purdue University
- West Lafayette
- USA
| | - Chuanchao Zhang
- Research Center of Laser Fusion
- China Academy of Engineering Physics
- Mianyang
- China
| | - Zhilei Sui
- Institute of Fluid Physics
- China Academy of Engineering Physics
- Mianyang
- China
| | - Meng Hou
- Department of Physics
- University of Science and Technology of China
- Hefei
- China
| | - Rucheng Dai
- The Centre for Physical Experiments
- University of Science and Technology of China
- Hefei
- China
| | - Zhongping Wang
- The Centre for Physical Experiments
- University of Science and Technology of China
- Hefei
- China
| | - Xianxu Zheng
- Institute of Fluid Physics
- China Academy of Engineering Physics
- Mianyang
- China
| | - Zengming Zhang
- The Centre for Physical Experiments
- University of Science and Technology of China
- Hefei
- China
- Key Laboratory of Strongly-Coupled Quantum Matter Physics
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25
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Whittleton SR, Otero-de-la-Roza A, Johnson ER. Exchange-Hole Dipole Dispersion Model for Accurate Energy Ranking in Molecular Crystal Structure Prediction II: Nonplanar Molecules. J Chem Theory Comput 2017; 13:5332-5342. [PMID: 28933853 DOI: 10.1021/acs.jctc.7b00715] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The crystal structure prediction (CSP) of a given compound from its molecular diagram is a fundamental challenge in computational chemistry with implications in relevant technological fields. A key component of CSP is the method to calculate the lattice energy of a crystal, which allows the ranking of candidate structures. This work is the second part of our investigation to assess the potential of the exchange-hole dipole moment (XDM) dispersion model for crystal structure prediction. In this article, we study the relatively large, nonplanar, mostly flexible molecules in the first five blind tests held by the Cambridge Crystallographic Data Centre. Four of the seven experimental structures are predicted as the energy minimum, and thermal effects are demonstrated to have a large impact on the ranking of at least another compound. As in the first part of this series, delocalization error affects the results for a single crystal (compound X), in this case by detrimentally overstabilizing the π-conjugated conformation of the monomer. Overall, B86bPBE-XDM correctly predicts 16 of the 21 compounds in the five blind tests, a result similar to the one obtained using the best CSP method available to date (dispersion-corrected PW91 by Neumann et al.). Perhaps more importantly, the systems for which B86bPBE-XDM fails to predict the experimental structure as the energy minimum are mostly the same as with Neumann's method, which suggests that similar difficulties (absence of vibrational free energy corrections, delocalization error,...) are not limited to B86bPBE-XDM but affect GGA-based DFT-methods in general. Our work confirms B86bPBE-XDM as an excellent option for crystal energy ranking in CSP and offers a guide to identify crystals (organic salts, conjugated flexible systems) where difficulties may appear.
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Affiliation(s)
- Sarah R Whittleton
- Department of Chemistry, Dalhousie University , 6274 Coburg Road, Halifax, Nova Scotia, Canada B3H 4R2
| | - A Otero-de-la-Roza
- Department of Chemistry, University of British Columbia , Okanagan, 3247 University Way, Kelowna, British Columbia, Canada VIV 1V7
| | - Erin R Johnson
- Department of Chemistry, Dalhousie University , 6274 Coburg Road, Halifax, Nova Scotia, Canada B3H 4R2
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26
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Connor LE, Morrison CA, Oswald IDH, Pulham CR, Warren MR. Carbon dioxide binary crystals via the thermal decomposition of RDX at high pressure. Chem Sci 2017; 8:4872-4878. [PMID: 28959411 PMCID: PMC5603901 DOI: 10.1039/c7sc01379e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/03/2017] [Indexed: 11/21/2022] Open
Abstract
A carbon dioxide and nitrous oxide solid solution has been captured in a diamond anvil cell following the thermal decomposition of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) at high temperatures and pressures. This is the first time a carbon dioxide binary solid has been observed at high pressure. This observation has stimulated low temperature crystallographic studies of this binary system using recently developed gas absorption apparatus and computational modelling.
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Affiliation(s)
- L E Connor
- Strathclyde Institute of Pharmacy and Biomedical Sciences , University of Strathclyde , 161 Cathedral Street , Glasgow , G4 0RE , UK .
| | - C A Morrison
- School of Chemistry , Centre for Science at Extreme Conditions , The University of Edinburgh , King's Buildings , David Brewster Road , Edinburgh EH9 3FJ , UK
| | - I D H Oswald
- Strathclyde Institute of Pharmacy and Biomedical Sciences , University of Strathclyde , 161 Cathedral Street , Glasgow , G4 0RE , UK .
| | - C R Pulham
- School of Chemistry , Centre for Science at Extreme Conditions , The University of Edinburgh , King's Buildings , David Brewster Road , Edinburgh EH9 3FJ , UK
| | - M R Warren
- Diamond Light Source , Harwell Science and Innovation Campus , Didcot , Oxfordshire OX11 0DE , UK
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27
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Whittleton SR, Otero-de-la-Roza A, Johnson ER. Exchange-Hole Dipole Dispersion Model for Accurate Energy Ranking in Molecular Crystal Structure Prediction. J Chem Theory Comput 2017; 13:441-450. [PMID: 27977188 DOI: 10.1021/acs.jctc.6b00679] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Accurate energy ranking is a key facet to the problem of first-principles crystal-structure prediction (CSP) of molecular crystals. This work presents a systematic assessment of B86bPBE-XDM, a semilocal density functional combined with the exchange-hole dipole moment (XDM) dispersion model, for energy ranking using 14 compounds from the first five CSP blind tests. Specifically, the set of crystals studied comprises 11 rigid, planar compounds and 3 co-crystals. The experimental structure was correctly identified as the lowest in lattice energy for 12 of the 14 total crystals. One of the exceptions is 4-hydroxythiophene-2-carbonitrile, for which the experimental structure was correctly identified once a quasi-harmonic estimate of the vibrational free-energy contribution was included, evidencing the occasional importance of thermal corrections for accurate energy ranking. The other exception is an organic salt, where charge-transfer error (also called delocalization error) is expected to cause the base density functional to be unreliable. Provided the choice of base density functional is appropriate and an estimate of temperature effects is used, XDM-corrected density-functional theory is highly reliable for the energetic ranking of competing crystal structures.
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Affiliation(s)
- Sarah R Whittleton
- Department of Chemistry, Dalhousie University , 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
| | - A Otero-de-la-Roza
- Department of Chemistry, University of British Columbia, Okanagan , 3247 University Way, Kelowna, British Columbia V1V 1V7, Canada
| | - Erin R Johnson
- Department of Chemistry, Dalhousie University , 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2, Canada
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28
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Ghosh M, Banerjee S, Shafeeuulla Khan MA, Sikder N, Sikder AK. Understanding metastable phase transformation during crystallization of RDX, HMX and CL-20: experimental and DFT studies. Phys Chem Chem Phys 2016; 18:23554-71. [PMID: 27506267 DOI: 10.1039/c6cp02185a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multiphase growth during crystallization severely affects deliverable output of explosive materials. Appearance and incomplete transformation of metastable phases are a major source of polymorphic impurities. This article presents a methodical and molecular level understanding of the metastable phase transformation mechanism during crystallization of cyclic nitramine explosives, viz. RDX, HMX and CL-20. Instantaneous reverse precipitation yielded metastable γ-HMX and β-CL-20 which undergo solution mediated transformation to the respective thermodynamic forms, β-HMX and ε-CL-20, following 'Ostwald's rule of stages'. However, no metastable phase, anticipated as β-RDX, was evidenced during precipitation of RDX, which rather directly yielded the thermodynamically stable α-phase. The γ→β-HMX and β→ε-CL-20 transformations took 20 and 60 minutes respectively, whereas formation of α-RDX was instantaneous. Density functional calculations were employed to identify the possible transition state conformations and to obtain activation barriers for transformations at wB97XD/6-311++G(d,p)(IEFPCM)//B3LYP/6-311G(d,p) level of theory. The computed activation barriers and lattice energies responsible for transformation of RDX, HMX and CL-20 metastable phases to thermodynamic ones conspicuously supported the experimentally observed order of phase stability. This precise result facilitated an understanding of the occurrence of a relatively more sensitive and less dense β-CL-20 phase in TNT based melt-cast explosive compositions, a persistent and critical problem unanswered in the literature. The crystalline material recovered from such compositions revealed a mixture of β- and ε-CL-20. However, similar compositions of RDX and HMX never showed any metastable phase. The relatively long stability with the highest activation barrier is believed to restrict complete β→ε-CL-20 transformation during processing. Therefore a method is suggested to overcome this issue.
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Affiliation(s)
- Mrinal Ghosh
- High Energy Materials Research Laboratory (Defence Research & Development Organization), Pune, 411 021, India.
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29
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Steele BA, Oleynik II. New phase of ammonium nitrate: A monoclinic distortion of AN-IV. J Chem Phys 2016; 143:234705. [PMID: 26696068 DOI: 10.1063/1.4937420] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A new phase of ammonium nitrate (AN) is found using first principles evolutionary crystal structure search. It is this polymorph that is associated with the phase transition to previously unidentified phase, which was detected in experiment at 17 GPa upon appearance of the two extra peaks in Raman spectrum. The new phase has a monoclinic unit cell in the P21/m space group symmetry (AN-P21/m) and is similar to the known phase IV of AN (AN-IV) except the ammonium molecules are oriented differently relative to the nitrate molecules. The calculated free energy of AN-P21/m is found to be lower than AN-IV at pressures above 10.83 GPa. The equation of state of both AN-P21/m and AN-IV phases (volume vs hydrostatic pressure at room temperature) has been obtained within the quasi-harmonic approximation. The calculated Raman spectrum of both AN-P21/m and AN-IV as a function of pressure is in a good agreement with experiment. The energetic competitiveness of AN-IV and AN-P21/m at ambient conditions suggests a possibility of the phase transition in a small pressure-temperature range near ambient pressure and temperature.
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Affiliation(s)
- Brad A Steele
- Department of Physics, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, USA
| | - Ivan I Oleynik
- Department of Physics, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, USA
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30
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Subramanian G, Mathew N, Leiding J. A generalized force-modified potential energy surface for mechanochemical simulations. J Chem Phys 2015; 143:134109. [PMID: 26450294 DOI: 10.1063/1.4932103] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Gopinath Subramanian
- School of Polymers and High Performance Materials, University of Southern Mississippi, Hattiesburg, Mississippi 39402, USA
| | - Nithin Mathew
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| | - Jeff Leiding
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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31
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McGregor L, Rychkov DA, Coster PL, Day S, Drebushchak VA, Achkasov AF, Nichol GS, Pulham CR, Boldyreva EV. A new polymorph of metacetamol. CrystEngComm 2015. [DOI: 10.1039/c5ce00910c] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The existence of a new polymorph of metacetamol together with its properties are reported for the first time.
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Affiliation(s)
- Lindsay McGregor
- School of Chemistry and Centre for Science at Extreme Conditions
- The University of Edinburgh
- King's Buildings
- Edinburgh, UK
- REC-008
| | - Denis A. Rychkov
- REC-008
- Novosibirsk State University
- Novosibirsk, Russia
- Institute of Solid State Chemistry and Mechanochemistry
- Novosibirsk, Russia
| | - Paul L. Coster
- School of Chemistry and Centre for Science at Extreme Conditions
- The University of Edinburgh
- King's Buildings
- Edinburgh, UK
| | - Sarah Day
- Diamond Light Source
- Harwell Science & Innovation Campus
- Didcot, UK
| | - Valeri A. Drebushchak
- REC-008
- Novosibirsk State University
- Novosibirsk, Russia
- V.S. Sobolev Institute of Geology and Mineralogy of the Russian Academy of Sciences
- Novosibirsk, Russia
| | | | - Gary S. Nichol
- School of Chemistry and Centre for Science at Extreme Conditions
- The University of Edinburgh
- King's Buildings
- Edinburgh, UK
| | - Colin R. Pulham
- School of Chemistry and Centre for Science at Extreme Conditions
- The University of Edinburgh
- King's Buildings
- Edinburgh, UK
| | - Elena V. Boldyreva
- REC-008
- Novosibirsk State University
- Novosibirsk, Russia
- Institute of Solid State Chemistry and Mechanochemistry
- Novosibirsk, Russia
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32
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Wu Q, Zhu W, Xiao H. DFT study of structural, electronic, and absorption properties of crystalline β-RDX under pressures. CAN J CHEM 2013. [DOI: 10.1139/cjc-2013-0174] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The structural, electronic, and absorption properties of crystalline hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) under hydrostatic pressure of 0–50 GPa were studied using density functional theory. As the pressure increases, the lattice constants and the unit cell volume decrease gradually. The compressibility of RDX crystal is anisotropic. The different changing trends of bond lengths and bond angles under pressures show that both the ring opening and the N–NO2 cleavage are possible to trigger the RDX decomposition. The interactions between electrons, especially for the valence electrons, are strengthened under the influence of pressure. The absorption spectra of RDX display more and stronger bands in the fundamental absorption region at high pressure.
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Affiliation(s)
- Qiong Wu
- Institute for Computation in Molecular and Materials Science and Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Weihua Zhu
- Institute for Computation in Molecular and Materials Science and Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Heming Xiao
- Institute for Computation in Molecular and Materials Science and Department of Chemistry, Nanjing University of Science and Technology, Nanjing 210094, China
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33
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Pereverzev A, Sewell TD, Thompson DL. Molecular dynamics study of the pressure-dependent terahertz infrared absorption spectrum of α- and γ-RDX. J Chem Phys 2013; 139:044108. [DOI: 10.1063/1.4813795] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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34
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Chen XF, Yang K, Wang BZ. Mechanisms and risk assessments on the N-nitration of N-acetylhexahydro-s-triazines: understanding the preparation of RDX (2). J Phys Chem A 2013; 117:5007-14. [PMID: 23721188 DOI: 10.1021/jp4012203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Although the N-nitration by nitric acid is widely used to synthesize nitramines in biological, medical, and explosive industries, little is known about the microscopic behavior when the nitrated substrates are tertiary amines. Hexahydro-1,3,5-triacetyl-s-triazine (TRAT) nitrated into hexahydro-1,3,5-trinitro-s-triazine (RDX) was theoretically investigated at the MP2/cc-PVDZ level. An O-to-N transnitration mechanism was put forward for the N-nitration of N-acetyl tertiary amines, including the formation of diverse complexes R'N(COCH3)RNO2(+) and deacetylate. The electron transfer results in the complex formation, and the acetyl-to-nitro electrophilic displacement leads to deacetylate. Presumably, the carbonyl groups (C═O) in N-acetyl tertiary amines serve as the hinged joint in the electron transfer. Three successive N-nitrations transform TRAT into RDX; their electron transfers are strongly exothermic by -21.1, -19.5, and -15.4 kcal/mol relative to TRAT + 3NO2(+), repectively, and their electrophilic displacements possess low activation Gibbs free energies of 9.0, 6.8, and 7.5 kcal/mol relative to the σ-complexes 6, 11, and 14, respectively. The rate constants of the single electron transfer (SET) and the acetyl-to-nitro displacement were estimated roughly by Marcus and transition-state (TS) theories, respectively, indicating that they are both fast with the strong exothermicity. The available experimental phenomena were well interpreted by the computational results.
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Affiliation(s)
- Xiao-Fang Chen
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, People's Republic of China
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35
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Ye CC, Zhao FQ, Xu SY, Ju XH. Adsorption and decomposition mechanism of hexogen (RDX) on Al(111) surface by periodic DFT calculations. J Mol Model 2013; 19:2451-8. [PMID: 23435519 DOI: 10.1007/s00894-013-1796-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Accepted: 02/05/2013] [Indexed: 11/26/2022]
Affiliation(s)
- Cai-Chao Ye
- Key Laboratory of Soft Chemistry and Functional Materials of MOE, School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, People's Republic of China
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36
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Vibrational spectra of an RDX film over an aluminum substrate from molecular dynamics simulations and density functional theory. J Mol Model 2012; 19:2773-8. [PMID: 23086462 DOI: 10.1007/s00894-012-1623-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 10/01/2012] [Indexed: 10/27/2022]
Abstract
We report calculated vibrational spectra in the range of 0-3,500 cm(-1) of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) molecules adsorbed on a model aluminum surface. A molecular film was modeled using two approaches: (1) density functional theory (DFT) was used to optimize a single RDX molecule interacting with its periodic images, and (2) a group of nine molecules extracted from the crystal structure was deposited on the surface and interacted with its periodic images via molecular dynamics (MD) simulations. In both cases, the molecule was initialized in the AAA conformer geometry having the three nitro groups in axial positions, and kept that conformation in the DFT examination, but some molecules were found to change to the AAE conformer (two nitro groups in axial and one in equatorial position) in the MD analysis. The vibrational spectra obtained from both methods are similar to each other, except in the regions where collective RDX intermolecular interactions (captured by MD simulations) are important, and compare fairly well with experimental findings.
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Goldberg IG, Vila FD, Jach T. Surface Effects on the Crystallization of Cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) and the Consequences for its N K X-ray Emission Spectrum. J Phys Chem A 2012; 116:9897-9. [DOI: 10.1021/jp306978x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ilana G. Goldberg
- Transportation Security Laboratory, Atlantic City, New Jersey 08405, United
States
| | - Fernando D. Vila
- Department
of Physics, University of Washington, Seattle, Washington 98195, United States
| | - Terrence Jach
- Material Measurement Laboratory, National Institute of Standards & Technology, Gaithersburg, Maryland 20899-8371, United States
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Dreger ZA, McCluskey MD, Gupta YM. High pressure-high temperature decomposition of γ-cyclotrimethylene trinitramine. J Phys Chem A 2012; 116:9680-8. [PMID: 22971173 DOI: 10.1021/jp307373v] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Decomposition of γ-cyclotrimethylene trinitramine (γ-RDX) under high pressure-high temperature conditions was examined to elucidate the reactive behavior of RDX crystals. Vibrational spectroscopy measurements were obtained for single crystals in a diamond anvil cell (DAC) at pressures from 6 to 12 GPa and temperatures up to 600 K. Global decomposition rates, activation energies, and activation volumes at several pressures and temperatures below the P-T locus for the γ-RDX decomposition were obtained. Similar to ε-RDX, but in contrast to α-RDX, we found that pressure decelerates the decomposition of γ-RDX. The decomposition deceleration with pressure in the γ-phase can be attributed to pressure-inhibiting bond homolysis step(s). The main decomposition species were identified as N(2)O, CO(2), and H(2)O, in accord with the species reported for the α-phase decomposition at high pressures. This work complements previous studies on RDX at HP-HT conditions and provides comprehensive results on the reactive behavior of γ-RDX; the γ-phase plays a key role in RDX decomposition at P-T conditions relevant to shock wave initiation.
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Affiliation(s)
- Zbigniew A Dreger
- Institute for Shock Physics and Department of Physics, Washington State University, Pullman, Washington 99164-2816, USA.
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Dreger ZA, Gupta YM. Decomposition of γ-Cyclotrimethylene Trinitramine (γ-RDX): Relevance for Shock Wave Initiation. J Phys Chem A 2012; 116:8713-7. [DOI: 10.1021/jp306589h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zbigniew A. Dreger
- Institute for Shock Physics and Department
of Physics, Washington State University, Pullman, Washington 99164-2816, United States
| | - Yogendra M. Gupta
- Institute for Shock Physics and Department
of Physics, Washington State University, Pullman, Washington 99164-2816, United States
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40
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Emmons ED, Guicheteau JA, Fountain AW, Christesen SD. Comparison of visible and near-infrared Raman cross-sections of explosives in solution and in the solid state. APPLIED SPECTROSCOPY 2012; 66:636-643. [PMID: 22732533 DOI: 10.1366/11-06549] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Raman cross-sections of explosives in solution and in the solid state have been measured using visible and near-infrared excitation via secondary calibration. These measurements are valuable for both fundamental scientific purposes and applications in the standoff detection of explosives. The explosive compounds RDX, HMX, TNT, 2,4-DNT, 2,6-DNT, and ammonium nitrate were measured using discrete excitation wavelengths ranging from 532 nm to 785 nm. A comparison of the spectral features and cross-sections between the solid state and solution was performed. Comparison is also made to cross-sections measured with deep ultraviolet excitation.
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Affiliation(s)
- Erik D Emmons
- Science Applications International Corporation, Gunpowder Branch, Aberdeen Proving Ground, Maryland 21010-5424, USA
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41
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Liu Y, Du H, Wang G, Gong X, Wang L. Comparative theoretical studies of high pressure effect on polymorph I of 2,2′,4,4′,6,6′-hexanitroazobenzene crystal. Struct Chem 2012. [DOI: 10.1007/s11224-012-9963-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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42
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Mathew N, Picu RC. Molecular conformational stability in cyclotrimethylene trinitramine crystals. J Chem Phys 2011; 135:024510. [DOI: 10.1063/1.3609769] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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43
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Munday LB, Chung PW, Rice BM, Solares SD. Simulations of High-Pressure Phases in RDX. J Phys Chem B 2011; 115:4378-86. [DOI: 10.1021/jp112042a] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lynn B. Munday
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, United States
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Peter W. Chung
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, United States
| | - Betsy M. Rice
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, United States
| | - Santiago D. Solares
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, United States
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44
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Chen XF, Wang BZ, Han KL. A reaction of formaldehyde with acetonitrile: understanding the preparation of RDX (I). RSC Adv 2011. [DOI: 10.1039/c1ra00239b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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45
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Bujak M, Bläser D, Katrusiak A, Boese R. Conformational polymorphs of 1,1,2,2-tetrachloroethane: pressure vs. temperature. Chem Commun (Camb) 2011; 47:8769-71. [DOI: 10.1039/c1cc10689a] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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46
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Dreger ZA, Gupta YM. Phase Diagram of Hexahydro-1,3,5-trinitro-1,3,5-triazine Crystals at High Pressures and Temperatures. J Phys Chem A 2010; 114:8099-105. [DOI: 10.1021/jp105226s] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zbigniew A. Dreger
- Institute for Shock Physics and Department of Physics, Washington State University, Pullman, Washington 99164-2816
| | - Yogendra M. Gupta
- Institute for Shock Physics and Department of Physics, Washington State University, Pullman, Washington 99164-2816
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47
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Dreger ZA, Gupta YM. Raman Spectroscopy of High-Pressure−High-Temperature Polymorph of Hexahydro-1,3,5-trinitro-1,3,5-triazine (ε-RDX). J Phys Chem A 2010; 114:7038-47. [DOI: 10.1021/jp102668d] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zbigniew A. Dreger
- Institute for Shock Physics and Department of Physics, Washington State University, Pullman, Washington 99164-2816
| | - Yogendra M. Gupta
- Institute for Shock Physics and Department of Physics, Washington State University, Pullman, Washington 99164-2816
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48
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Millar DI, Marshall WG, Oswald ID, Pulham CR. High-pressure structural studies of energetic materials. CRYSTALLOGR REV 2010. [DOI: 10.1080/08893110903443422] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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49
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Infante-Castillo R, Pacheco-Londoño LC, Hernández-Rivera SP. Monitoring the α→β solid–solid phase transition of RDX with Raman spectroscopy: A theoretical and experimental study. J Mol Struct 2010. [DOI: 10.1016/j.molstruc.2010.02.021] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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50
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Millar DIA, Maynard-Casely HE, Kleppe AK, Marshall WG, Pulham CR, Cumming AS. Putting the squeeze on energetic materials—structural characterisation of a high-pressure phase of CL-20. CrystEngComm 2010. [DOI: 10.1039/c002701d] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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