摘要
偶氮四唑叠氮基甲脒AFZT的爆轰性能表现优异,在高能炸药领域中具有广阔的应用前景.本文采用基于密度泛函理论的第一性原理方法计算了 AFZT在0～50 GPa压力下的晶体结构、电子性质以及氢键相互作用,并分析了这些性质在压力下的变化规律.在压力的作用下,AFZT晶体在5 GPa下发生了结构转变并伴随着电子结构中带隙值的突变,其带隙先减小后增大再减小,总态密度的峰值随着压力的增加而减小.结构中叠氮甲脒阳离子上的N8-N9与N9-N10键在压力下表现得最稳定,N-H N类型的氢键在所有相互作用中占据主导地位.此外,AFZT结构沿不同晶轴压缩的难易程度与此方向上氢键相互作用分布的疏密有关,并且其氢键主要沿xz平面分布而在y轴上分布极少,这导致了它沿y轴方向最易被压缩.
Abstract
Bis(azidoformamidinium)5,5'-azotetrazolate(AFZT)of azotetrazole nonmetallic energetic salts has excellent detonation performance and has broad application prospects in the field of high explosives.In this pa-per,the crystal structure,electronic properties and hydrogen bond interactions of AFZT under 0～50 GPa pres-sure are calculated by the first-principle method based on density functional theory,and the variation laws of these properties under pressure are analyzed.The AFZT structure obtained by Generalized Gradient Approxima-tion-Perdew Burke Ernzerhof(GGA-PBE)combined method is in good agreement with experimental results,and phonon spectrum shows that it is stable at zero pressure.At zero pressure,AFZT is an indirect bandgap com-pound with a bandgap value of 1.962 eV,and there are eight hydrogen bond interactions between anions and cat-ions.Under pressure,the AFZT structure undergo structural transformation at 5 GPa,accompanied by the sud-den change of band gap value in the electronic structure.The band gap first decreases,then increases and then decreases,and the peak value of total density of states decreases with the increasing pressure.The N8-N9 and N9-N10 bonds on the cation are the most stable under pressure,and the hydrogen bond interactions of N-H…N type play the dominant role in AFZT structure.In addition,AFZT structure shows anisotropy when com-pressed,and the difficulty of compression along a crystal axis is related to the density of hydrogen bond interac-tion distribution in this direction.Its hydrogen bonds are mainly distributed along the xz plane and rarely in the y-axis direction,which makes AFZT most likely to be compressed along the y-axis direction.
基金项目
国家自然科学基金(12072299)
国家自然科学基金(11902276)
国防科工局基础科研项目(JCKYS2019212007)
中央高校基本科研业务费专项资金(2682020ZT102)
中央高校基本科研业务费专项资金(2682021CX075)
国家科技期刊平台
NSTL
维普
万方数据