Quantum-chemical DFT calculations of the molecular structure of N2O5 in the gas and solid phases

By functional density quantum-chemical method (DFT/B3LYP using the 6-311++G(3df)) it has been shown that the molecular structures of N₂O₅ with C_s and C₂ symmetries are energetically equivalent. It follows from calculations of the vibrational frequencies that both structures are characterized by potential energy minima and correspond to stationary states of the N₂O₅ molecule. It is proposed, on the basis of a comparison of the calculated and experimental vibrational spectra of N₂O₅, that dinitrogen pentaoxide exists in the gas phase as an equimolecular mixture of N₂O₅ molecules with Cs and C₂ symmetry, while in the solid phase it is characterized by the C₂ molecular structure. __________ Translated from Teoreticheskaya I éksperimental’naya Khimiya, Vol. 43, No. 1, pp. 58–63, January–February, 2007.