Electronic, mechanical, vibrational, and thermodynamic properties of 5,5'-bis(1,4-dinitro-1H-pyrazol-3-yl)-2,2'-bi(1,3,4-oxadiazole) based on first‑principles calculations.

CONTEXT: 5,5'-Bis(1,4-dinitro-1H-pyrazol-3-yl)-2,2'-bi(1,3,4-oxadiazole) (C10H2N12O10) is a bis-heterocyclic compound that combines pyrazole, 1,3,4-oxadiazole, and nitro groups within a single framework. This combination offers a trade-off between high energy density and safety, a key objective in energetic materials research. Using first-principles density functional theory, we investigate the structural, electronic, mechanical, and vibrational properties of this compound. The results reveal that C10H2N12O10 is structurally stable, intrinsically ductile, and dynamically stable. We also clarify its electronic structure and chemical bonding characteristics, and assign the main vibrational modes. Together, these findings help establish structure-property relationships for this material and provide a theoretical basis for its potential use in high-performance energetic systems.

METHODS

First-principles DFT calculations were carried out using the CASTEP code. The exchange-correlation potential was treated with the PBE functional within the GGA, and van der Waals interactions were incorporated using Grimme's DFT-D3 scheme. Norm-conserving pseudopotentials generated according to the Hamann scheme were employed to describe core-valence electron interactions. A plane-wave basis set with a kinetic energy cutoff of 830 eV was used, and Brillouin zone sampling was performed with a 1 × 2 × 1 Monkhorst-Pack k-point grid.