Materials Data on Hf2NiS4 by Materials Project
Hf2NiS4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Hf is bonded to six S atoms to form HfS6 octahedra that share corners with six equivalent NiS6 octahedra, edges with six equivalent HfS6 octahedra, and a faceface with one NiS6 octahedra. The corner-sharing octahedra tilt angles range from 47–49°. There are a spread of Hf–S bond distances ranging from 2.54–2.58 Å. Ni is bonded to six S atoms to form NiS6 octahedra that share corners with twelve equivalent HfS6 octahedra, edges with two equivalent NiS6 octahedra, and faces with two equivalent HfS6 octahedra. The corner-sharing octahedra tilt angles range from 47–49°. There are two shorter (2.39 Å) and four longer (2.46 Å) Ni–S bond lengths. There are two inequivalent S sites. In the first S site, S is bonded in a rectangular see-saw-like geometry to three equivalent Hf and one Ni atom. In the second S site, S is bonded to three equivalent Hf and two equivalent Ni atoms to form a mixture of distorted corner and edge-sharing SHf3Ni2 square pyramids.