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Guo Z, Wang X, Hao G, Xiao L, Feng X, Yang J, Jiang W. Structural and decomposition analysis of TKX-50 with vacancy defects: insights from DFT and AIMD simulations. Phys Chem Chem Phys 2024; 26:9665-9674. [PMID: 38470042 DOI: 10.1039/d3cp05209e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Vacancy defects are commonly present in crystals of energetic materials, and significantly influence the structural stability and decomposition mechanisms. However, there is a lack of profound understanding regarding the introduction of vacancy defects in energetic ionic salt, dihydroxylammonium 5,5'-bitetrazole-1,1'-dioxide (TKX-50). Due to the 1 : 2 ratio of anions to cations, TKX-50 possesses a more complex distribution of vacancy defects compared to traditional energetic materials. Based on the density functional theory method, the relatively favorable thermodynamic formation of vacancy defect distributions was revealed. The noncovalent interactions within the system, as well as the planarity of the anions, were investigated to understand the structural stability of TKX-50. Through ab initio molecular dynamics simulations, we discovered that vacancy defects can expedite the proton transfer during the initial decomposition stage of TKX-50 and affect the pathways of proton transfer. In the subsequent decomposition process, introduction of vacancy defects in the TKX-50 crystal leads to an earlier onset of ring-opening reactions and accelerates the appearance of decomposition products. The findings have the potential to provide insights into modeling vacancy defects in energetic ionic salts and reveal the impact of such defects on the structural stability and decomposition mechanisms of these materials.
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Affiliation(s)
- Zhiwei Guo
- National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Xiaohe Wang
- National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Gazi Hao
- National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Lei Xiao
- National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Xiaojun Feng
- Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
| | - Junqing Yang
- National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094, China
- School of Mechanical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Wei Jiang
- National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094, China
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Qin H, Zheng Q, Zhou YX, Li F, Li HD, Liu QJ, Liu ZT. The structural and electronic properties of (001) surface of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) with first-principles calculations. J Mol Model 2023; 30:7. [PMID: 38091173 DOI: 10.1007/s00894-023-05800-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/29/2023] [Indexed: 01/11/2024]
Abstract
CONTEXT 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is a typical insensitive energetic material. It can be used in explosive formulations, such as PBX-9502 and LX-17-0. TATB is an intriguing and unusual explosive for another reason: it crystallizes into a wide array of planar hydrogen bonds, forming a graphite-like layered structure. Therefore, TATB is one of the important research objects, and its surface structure needs to be deeply understood. In this research work, the electronic and energetic properties of TATB (001) surface are explored. METHODS In this paper, the structural, electronic, energetic properties and impact sensitivity of TATB (001) surface structure at 0 and -3 GPa along with x-axis were calculated in this study using the first-principles calculations. The calculations in this paper are performed in the CASTEP code, which is based on the density functional theory with the first-principles calculation method using the plan-wave pseudopotential approach. The exchange-correlation interaction was adopted by the generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) functional. The DFT-D method with the Grimme correction accurately models van der Waals interactions. To model the surface structures of TATB, the planar slab method was employed. We constructed TATB (001) periodic slabs including three layers with a 15-Å vacuum layer.
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Affiliation(s)
- Han Qin
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu, 610039, People's Republic of China.
| | - Qian Zheng
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu, 610039, People's Republic of China
| | - Ying-Xu Zhou
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu, 610039, People's Republic of China
| | - Fei Li
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu, 610039, People's Republic of China
| | - Hui-Dong Li
- School of Science, Key Laboratory of High Performance Scientific Computation, Xihua University, Chengdu, 610039, People's Republic of China.
| | - Qi-Jun Liu
- Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China
| | - Zheng-Tang Liu
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
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Fan J, Wang P, Gao N. Pressure-dependent structure and electronic properties of energetic NTO crystals dominated by hydrogen-bonding interactions. Phys Chem Chem Phys 2023; 25:14359-14367. [PMID: 37183725 DOI: 10.1039/d3cp01518a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
3-Nitro-1,2,4-trihydroxy-5-one (NTO), a highly potential high-performance explosive with good thermal stability and low sensitivity, has attracted much attention for its physicochemical properties in recent years. In this work, the pressure effect of the vibrational and electronic properties is investigated to understand the intermolecular interaction of NTO under hydrostatic compression. From the pressure-dependent Raman and infrared spectra, we found that the red-shifts of high-wavenumber N-H stretching modes and the discontinuous shifts of all Raman modes occur at 3 and 6 GPa, indicating an evident change of molecular configuration and intermolecular interaction upon compression. Based on structural analysis, the changes of intra- and intermolecular hydrogen bonds (HBs) are closely relevant to the anomalous rotation of the nitro group and the lengthening of N-H bonds, which can be treated as an important step of a potential structural transformation of NTO. Moreover, intermolecular hydrogen-bonding interaction leads to the shrinkage of the band gap at 6 GPa, caused by the fast charge transfer of 0.07 e from the nitrogen heterocycle to the nitro group. These results manifest a non-covalent interaction mechanism for modulating the molecular configuration of EMs under pressure loading and provide vital insights into understanding the pressure effects for energetic molecular crystals.
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Affiliation(s)
- Junyu Fan
- Department of Physics, Taiyuan Normal University, Jinzhong, 030619, China
- Institute of Computational and Applied Physics, Taiyuan Normal University, Jinzhong, 030619, China
| | - Pengju Wang
- Zhejiang Laboratory, Hangzhou 311100, China
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian, 116024, China
| | - Nan Gao
- School of Materials Science and Engineering, Taizhou University, Taizhou 318000, China.
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High-pressure induced structural changes of energetic ionic salts: Dihydroxylammonium 3,3′-dinitro-5,5′-bis-1,2,4-triazole-1,1′-diolate (MAD-X1). Chem Phys 2023. [DOI: 10.1016/j.chemphys.2022.111727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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