Periodic DFT Studies Of High-Pressure Behavior Of Energetic Furazan Derivatives Crystals

Periodic density functional theory (DFT) method was used to study the crystal, molecular, and electronic structure, and optical absorption properties under hydrostatic pressure of0-100GPa, and the thermodynamics properties under ambient pressure of energetic crystalline1,4-dinitrofurazano[3,4-b]piperazine (DNFP), substituted furazan derivatives (DAF, ANF, AAF, and AMF), and azofurazan derivatives (DAAF and DAOAF). 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 DNFP was firstly optimized without any constraints. Then from this relaxed structure, we applied hydrostatic compression of1-100GPa to relax the crystal structure. After that, their electronic structure and optical absorption properties at different pressures were calculated. The thermodynamics properties of its decomposition reaction under ambient pressure were also investigated. Finally, the effects of different pressures on their structure and properties were discussed.2. The effects of different pressures on the crystal, molecular, and electronic structure of3,4-diaminofurazan (DAF),3-amino-4-nitrofurazan (ANF),3-azide-4-aminofurazan (AAF) and3-methyl-4-aminofurazan (AMF) were studied comparatively. The absorption spectra of the four crystals at different pressures were analyzed. The thermodynamic properties under ambient pressure were studied and the possibility of their decomposition reactions was distinguished. The relationships between their band structure and sensitivity were discussed.3. The crystal structure of DAAF (3,3’-diamino-4,4’-azoxyfurazan) and DAOAF (3,3-diamino-4,4-azofurazan) were fully relaxed. Then we applied hydrostatic compression of1-100GPa to their relaxed structure and relaxed their crystal structure. After that, the band structure, density of states, absorption spectra of the four crystals at different pressures and the thermodynamic properties under ambient pressure were calculatd. The effects of different pressures on their crystal, molecular, and electronic structure were analyzed. The thermodynamic properties of their decomposition reactions at ambient pressure were studied.