scientific comment
The noncentrosymmetric space group P3m but a pseudocentric cubic crystal structure were reported for the compound Ni5.20Sn8.7Zn4.16Cu1.04 [Larsson et al. (1994). Acta Cryst. C50, 9-12]. The recently described Ni2Sn2Zn shows a closely related structure, although it is centrosymmetric and contains additional voids which are partially occupied. Therefore, a new refinement of Ni5.20Sn8.7Zn4.16Cu1.04 based on the originally published structure factors was performed. The results indicate that the structure can indeed be described in the centrosymmetric space group Pmm; no justification for the absence of the inversion centre could be found within the accuracy of the available data. In comparison with Ni2Sn2Zn, slight but significant differences were confirmed; consequently, the two structures are topologically related but not isotypic.
Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S2053229614003660/eg3148sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S2053229614003660/eg3148Isup2.hkl |
CCDC reference: 987517