Superconducting non-centrosymmetric boride Mg10Ir19B16: crystal structure and chemical bonding

 

Chem. Met. Alloys 7 (2014) 74-84

 

Anastasia M. ALEKSEEVA, Andreas LEITHE-JASPER, Yuri PROTS, Walter SCHNELLE, Alim ORMECI, Evgeny V. ANTIPOV, Yuri GRIN

 

A single-phase sample of Mg10Ir19B16 was prepared from the elements by high-temperature treatment in sealed Ta containers. The crystal structure of Mg10Ir19B16 (space group I-43m, a = 10.5657(2) Å, Z = 2) was solved and refined using X-ray single crystal diffraction data. The chemical composition was confirmed by WDXS analysis. The absence of any significant homogeneity range was proven via lattice parameter determinations for samples of different nominal compositions. Electronic structure calculations and chemical bonding analysis by the ELI/ED approach revealed that the basis of the Mg10Ir19B16 structure is formed by a 3D anionic framework of covalent polar BIr bonds. Mainly ionic interactions were found between the Mg cations and the anionic framework, supported by additional dative Ir-Mg bonding.

 

 

QTAIM atomic basins and effective charges in Mg10Ir19B16.

 

Keywords

Superconducting boride / Crystal structure / Chemical bonding