Theoretical Studies Of The Structure And Properties Of Energetic Crystalline Furazan Derivatives At High Pressures

Periodic density functional theory with dispersion correction (DFT-D) method was used to study the structure and properties of energetic crystalline furazan derivatives benzotrifuroxan (BFT),3,3’-dinitroamino-4,4’-azoxyfurazan (DNOAAF), 3,3’-dinitro-4,4’-azoxyfurazan (DNOAF), and 3,4-bis(3-nitrofurazan-4-yl)furoxan (BNTF) under hydrostatic pressure. The effects of different pressures on their structure and properties were discussed. Our work may provide effective supplement to experimental work. The main contents of the thesis are as follows:1. The experimental crystal structure of BTF was optimized without any constraints using three DFT-D methods (PBE-G06, PBE-TS, and PW91-OBS) and a proper method was selected based on a comparison of computational and experimental results. Then from this relaxed structure, we relaxed the crystal structure of BTF under hydrostatic pressures of 0-190GPa. After that, their electronic structure and optical absorption properties at different pressures were calculated. Finally, the effects of different pressures on their structure and properties were discussed.2. According to the comparison of PBE-G06-, PBE-TS-, and PW91-OBS-relaxed and experimental structure of DNOAAF crystal, an optimal method was obtained. The crystal structure, electronic properties, and optical adsorption spectra were calculated under hydrostatic pressures of 0-190GPa. The effects of different pressures on their crystal, molecular, and electronic structure and optical adsorption properties were analyzed. The variation of its sensitivity and chemical bonds at high pressures were uncovered.3. In the pressure range of 1-190 GPa, the crystal structure of DNOAF was fully relaxed without any constraints. On the basis of the relaxed structure, their band structure, density of states, and optical adsorption properties were calculated. The variation trends of their crystal structure, molecular geometric parameters, band gaps, density of states, and optical adsorption coefficients with the increment of the pressure were summarized.4. The tests on the three methods of PBE-G06-, PBE-TS-, and PW91-OBS were performed to determine the optimal method. The pressures of 1-150 GPa ware applied to relax the crystal structure of BNTF. Then, their band gaps, density of states, and optical adsorption properties were calculated. Finally, the effects of the pressure on its structure and properties were discussed.