Charge Transfer in Be-Ru Compounds

During the investigation of the binary system Be-Ru two new phases - Be7Ru4 and Be12Ru7 - with similar compositions (63.6 at. % Be and 63.2 at. % Be, respectively), are discovered. They both represent new structural prototypes. The phases are located between Be2Ru (Fe2P-type structure) and Be3Ru2 (U3Si2-type structure) in the phase diagram. This explains why their crystal structures, solved and refined from single crystal X-ray diffraction data, are described as 2D intergrowth of Fe2P and U3Si2 motives. The calculated electronic density of stats (DOS) reveals pronounced minima in the vicinity of the Fermi level for both compounds. Position-space analysis of chemical bonding exhibits the formation of three- and four-atomic polar bonds, involving both, Ru and Be, atoms, and a strong charge transfer from Be to the more electronegative Ru. Be7Ru4 and Be12Ru7 are novel structural prototypes featuring an inhomogeneous 2D intergrowth of Fe2P- and U3Si2-type motifs. Chemical bonding analysis reveals the presence of polar multi-atomic bonds and charge transfer. Topological analysis of electron density in the Be-Ru compounds demonstrates non-linear change in the atomic volumina and complex variation of QTAIM atomic charges with composition.image