DFT studies on 7-nitrotetrazolo [1,5]furazano[4,5-b]pyridine 1-oxide: crystal structure,detonation properties,sensitivity and effect of hydrostatic compression

A new high energy density compound 7-nitrotetrazolo1,5]furazano4,5-b]pyridine 1-oxide (NFP) was studied. The molecular geometrical and electronic properties, heat of formation and detonation properties were predicted. Two crystal polymorphs of NFP were also predicted and compared well with experimental results. According to the constitution of the frontier energy bands, the tetrazol ring of NFP may be the active position of thermolysis. The calculated band gaps indicate the sensitivity of α-NFP is slightly lower than that of β-NFP. The effects of hydrostatic compression on the more stable form α-NFP were investigated in the pressure range of 0–100 GPa. α-NFP has an anisotropic compressibility. The band gap reduction is more pronounced in the low-pressure region than in the high-pressure region and the gap drops to nearly zero at 15 GPa, which means that the crystal changes its electronic character toward a metallic system. The analysis of density of states indicates that the electronic nonlocality increases under the influence of pressure.