Materials Data on Mg(NiS2)4 by Materials Project
Mg(NiS2)4 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Mg2+ is bonded to six equivalent S2- atoms to form MgS6 octahedra that share corners with six equivalent NiS6 octahedra and edges with six equivalent NiS6 octahedra. The corner-sharing octahedral tilt angles are 11°. All Mg–S bond lengths are 2.57 Å. There are two inequivalent Ni+3.50+ sites. In the first Ni+3.50+ site, Ni+3.50+ is bonded to six S2- atoms to form NiS6 octahedra that share edges with two equivalent MgS6 octahedra and edges with six NiS6 octahedra. There are four shorter (2.27 Å) and two longer (2.28 Å) Ni–S bond lengths. In the second Ni+3.50+ site, Ni+3.50+ is bonded to six equivalent S2- atoms to form NiS6 octahedra that share corners with six equivalent MgS6 octahedra and edges with six equivalent NiS6 octahedra. The corner-sharing octahedral tilt angles are 11°. All Ni–S bond lengths are 2.34 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ni+3.50+ atoms. In the second S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent Ni+3.50+ atoms.