Superconducting non-centrosymmetric boride Mg10Ir19B16:
crystal structure and chemical bonding
Chem.
Met. Alloys 7
(2014) 74-84
https://doi.org/10.30970/cma7.0275
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 B–Ir 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