2，6‐二氨基‐3，5‐二硝基吡嗪‐1‐氧化物（L L M‐105）是一种综合性能优良的新型高能钝感炸药，为了研究LLM‐105的分子结构特性，利用太赫兹时域光谱技术对该炸药在0.2～2.4 THz频率范围内的吸收光谱进行了探测，结果表明L L M‐105在该频率范围内出现了多个强度不同的特征吸收峰，分别位于1.27，1.59，2.00，2.08，2.20，2.29 THz处。基于密度泛函理论（DFT），借助Materials Studio 6.0量子化学软件对LLM‐105晶体在小于2.5 THz频率范围内的吸收光谱进行了模拟计算，计算结果中除了2.29 THz处吸收频率，其余5处与实验测得值均有很好的一致性，从理论角度验证了实验数据的准确性。完成了对实验太赫兹吸收光谱中特征吸收峰振动模式的分析和指认，结果表明L L M‐105太赫兹吸收特征峰的形成与分子振动密切相关，进一步为其分子结构变化的研究提供重要的实验手段与技术支撑。对于没有计算频率对应的2.29 T Hz处特征吸收峰，分析认为是由晶格振动或其他原因导致。%2 ,6‐diamino‐3 ,5‐dinitropyrazine‐1‐oxide (LLM‐105) ,a novel explosive with high energy and low sensibility .In order to study the molecular structure characteristics of the explosive ,the absorption spectra of LLM‐105 in the frequency range of 0.2~2.4 THz were detected by terahertz time‐domain spectroscopy (THz‐TDS) .The results showed that a number of characteris‐tic absorption peaks with different intensity located at 1.27 ,1.59 ,2.00 ,2.08 ,2.20 ,2.29 THz .The article also simulated the absorption spectra of LLM‐105 molecular crystal within 0.2~2.5 THz region by using Materials Studio 6.0 software based on density functional theory (DFT) ,and the simulated results agreed well with the experimental data except for the peak at 2.29 THz ,which verified theoretically the accuracy of the experimental data .In addition ,the vibrational modes of the characteristic peaks in the experimental absorption spectra were analyzed and identified ,the results showed that the forming of the characteris‐tic absorption peaks and the molecular vibration were closely related ,which further provided important laboratory and technology support for the study of the transformation of molecule structure of LLM‐105 .There was no simulated frequency agreed with the experimental absorption peak at 2.29 THz ,which may be caused by the vibration of the crystal lattice or other reasons .
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