Relaxed structure of typical nitro explosives in the excited state: Observation, implication and application

• Published in: Chemical physics letters Vol. 698; pp. 200 - 205
• Main Authors: Chu, Genbai, Yang, Zuhua, Xi, Tao, Xin, Jianting, Zhao, Yongqiang, He, Weihua, Shui, Min, Gu, Yuqiu, Xiong, Ying, Xu, Tao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.04.2018
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2018.02.030

[Display omitted] •Relaxed structures of nitro explosives in the excited state are investigated.•Typical nitro explosives exhibit a similar relaxation behavior.•Impact sensitivity is related to excitation energy of relaxed structure.•High sensitivity δ-HMX has a lower excitation energy for relaxed structure than β-HMX. Understanding the structural, geometrical, and chemical changes that occur after an electronic excitation is essential to elucidate the inherent mechanism of nitro explosives. Herein, relaxed structures of typical nitro explosives in the lowest singlet excited state are investigated using time-dependent density functional theory. During the excitation process, the nitro group is activated and relaxes via geometrical change. The five explosives RDX, HMX, CL-20, PETN, and LLM-105 exhibit similar relaxed structures, and the impact sensitivity is related to their excitation energy. High-sensitivity δ-HMX has a lower excitation energy for relaxed structure than β-HMX. This study offers novel insight into energetic materials.