The effect of hydrostatic pressure on melt-castable energetic materials bis-oxadiazole-bis-methylene dinitrate: A density functional theory study

Using density functional theory calculations, the structural and electronic properties of the melt-castable energetic materials of bis-oxadiazole-bis-methylene dinitrate (BODN) were studied. The calculated lattice parameters, molecular geometry and band gap by the semi-empirical dispersion (Grimme) corrected generalized gradient approximation functional of Perdew-Burke-Ernzerhof (GGA-PBE-G06) are in good agreement with experimental and theoretical results. Also, the pressure effect on BODN was studied in this work. It is found that although the calculated lattice parameters a, b and c are all decreased monotonically with pressure up to 25 GPa, the b-axis is the easiest compressible. The compression behaviors of geometry were investigated, and found the bond C1–N1 and C3–O2 respective in the oxadiazole and alkyl nitric ester groups were more compressible than the others. The molecular interactions were examined by the Hirshfeld surface and 2D-fingerprint analysis. Moreover, the predicted band gap under high-pressure conditions was discussed as well.