FOX-7: geometry, molecular structure and chemical bond

FOX-7 (1,1-diamino-2,2-dinitroethylene) recently is expected as a relatively new energetic material with highperformance and low sensitivity. The RHF and MP2 levels and DFT method with B3LYP functional with aug-cc-pVDZ basis set have been used to obtain optimized geometries and Rho functions (electron density distributions). Via fundamental physical theorems implemented in Quantum Theory of Atoms in Molecules (QTAIM), the structures, the physical nature of chemical bonds and all Bond Critical Points (BCPs) properties have been determined for cited species at the mentioned theoretical levels. In the present study, existence of intra-molecular hydrogen bonding and resonance due to "electron-withdrawing" nitro groups and "electrondonating" amine groups in ethene backbone is shown with AIM analysis and the resonance structures of FOX-7are obtained. In addition, the calculated wave numbers of vibrational normal modes (in gas phase) are compared with experimental IR spectrum of FOX-7.