Characterizing the oxygen-oxygen interaction in the dinitramide anion

Atomic interactions between oxygen atoms have been analyzed in terms of the Theory of Atoms in Molecules for the biguanidium dinitramide and biguanidium bis-dinitramide crystals. The electron density has been derived from X-ray diffraction data obtained at 90 K, and the potential energy density has been calculated using the density functional approach. Bond critical points have been found on the O(1)...O(4) interatomic line in both the electron density and potential energy density gradient fields. The bond path and its associated virial path have been obtained. The interaction has been identified as a bonding closed-shell type interaction.     

Atoms-in-molecules study of intra- and intermolecular bonding in the pentaerythritol tetranitrate crystal

Chemical bonding in the pentaerythritol tetranitrate crystal based on the experimental electron density obtained from X-ray diffraction data at 100 K and theoretical calculations at the experimental molecular geometry have been analyzed in terms of the Quantum Theory of Atoms in Molecules. Features of the intra- and intermolecular bond critical points and the oxygen atom lone-pair locations are discussed. Numerous intermolecular bonding interactions, including O...H and O...O, have been found and characterized. Atomic charges and atomic energies were integrated and compared with those for similar compounds. The N-O topological bond orders have been calculated for the first time, and the PETN atomic valences have been estimated.     

Chemical bonding in cesium uranyl chloride based on the experimental electron density distribution

Details of the electron density distribution in Cs(2)UO(2)Cl(4) have been obtained from an accurate X-ray diffraction experiment at 20 K. The electron density was described with the Hansen-Coppens multipole model. Topological analysis of the electron density confirms that the U-O bond is probably a triple bond, the U-Cl bonds are incipient covalent interactions, and the Cs-Cl and Cs-O interactions are of the closed-shell type. The results obtained serve as a proof of principle that electron density features related to chemical bonding may be obtained from X-ray data for even the heaviest elements.