Guo Xue-Ni, Chang Xiang-Hui, Bai Zhi-Xin, Liu Qi-Jun, Liu Zheng-Tang
Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China.
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China.
J Mol Model. 2024 Apr 19;30(5):140. doi: 10.1007/s00894-024-05914-3.
In order to study the relationship between the sensitivity and pressure of energetic materials, six kinds of energetic materials were selected as the research object. The crystal structure, electronic, and phonon properties under hydrostatic pressure of 0 ~ 45 GPa were calculated by first principles. The calculation results show that the lattice parameters and band gap values of these six energetic materials decrease with the increase of pressure. The peak of the density of states decreases and moves to the low energy direction, and the electrons become more active. Meanwhile, the effect of pressure on the sensitivity of the energetic materials is analyzed based on the multi-phonon up-pumping theory. The number of doorway modes and integral of projected phonon density of states under high pressure is calculated. The results show that both of them increase with the increase of pressure. And the smaller the value of the band gap, the larger the number of doorway modes and integral of projected phonon density of states, and the more sensitive the energetic material is.
All calculations are performed using the Materials Studio software based on density functional theory. The Perdew-Burke-Ernzerhof (PBE) functional of the generalized gradient approximation (GGA) is used to calculate the exchange correlation function, and the Grimme dispersion correction method is used to deal with the weak intermolecular interaction. The structure of the compound was optimized by BFGS algorithm. The linear response is used to calculate the phonon properties of energetic materials. The plane wave cutoff energy was set to 830 eV. The K-point grids of TATB, FOX-7, TNX, RDX, TNT, and HMX were chosen as 2 × 2 × 2, 2 × 2 × 1, 2 × 1 × 1, 1 × 1 × 1, 1 × 2 × 1, and 2 × 1 × 2.
为了研究含能材料的感度与压力之间的关系，选取了六种含能材料作为研究对象。采用第一性原理计算了0～45 GPa静水压力下这六种含能材料的晶体结构、电子和声子性质。计算结果表明，这六种含能材料的晶格参数和带隙值随压力的增加而减小。态密度峰值降低并向低能方向移动，电子变得更加活跃。同时，基于多声子上泵浦理论分析了压力对含能材料感度的影响。计算了高压下门道模式的数量和投影声子态密度积分。结果表明，二者均随压力的增加而增加。并且带隙值越小，门道模式的数量和投影声子态密度积分越大，含能材料越敏感。
所有计算均使用基于密度泛函理论的Materials Studio软件进行。采用广义梯度近似（GGA）的Perdew-Burke-Ernzerhof（PBE）泛函计算交换相关函数，并采用Grimme色散校正方法处理弱分子间相互作用。采用BFGS算法对化合物结构进行优化。采用线性响应计算含能材料的声子性质。平面波截止能量设置为830 eV。TATB、FOX-7、TNX、RDX、TNT和HMX的K点网格分别选为2×2×2、2×2×1、2×1×1、1×1×1、1×2×1和2×1×2。
