Study on regulation effect of external electric field on energetic material 1-methyl-2,4,5-Trinitroimidazole.

In this work, in order to explore the regulation effect of external electric field (EEF) on various properties of 1-methyl-2,4,5-trinitroimidazole (MTNI), density functional theory (DFT) was used to investigate the molecular structure, electronic structure, frontier molecular orbital (FMO) and ultraviolet-visible (UV-Vis) spectroscopy of MTNI under EEF. The results show that: (1) EEF significantly affects the geometric and electronic structure of MTNI, which in turn affects the sensitivity of MTNI. (2) When the EEF in the positive direction increases, the energy gap of MTNI decreases significantly and the total density of states (TDOS) turns to be dominated by the nitro groups. (3) EEF makes MTNI appear new absorption peak in visible light region and thus makes the MTNI display color. The generation of new absorption peaks is also dominated by the nitro groups. We also carefully analyzed how EEF deforms structure of the MTNI from the perspective of atomic forces and decomposition of energy variation.