Materials Data on Ni18Bi3AsS16 by Materials Project
Ni18Bi2AsS16Bi crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional and consists of two bismuth molecules and one Ni18Bi2AsS16 framework. In the Ni18Bi2AsS16 framework, there are three inequivalent Ni+1.78+ sites. In the first Ni+1.78+ site, Ni+1.78+ is bonded to one As3- and four S2- atoms to form a mixture of distorted face, edge, and corner-sharing NiAsS4 trigonal bipyramids. The Ni–As bond length is 2.46 Å. There are two shorter (2.27 Å) and two longer (2.38 Å) Ni–S bond lengths. In the second Ni+1.78+ site, Ni+1.78+ is bonded in a square co-planar geometry to four equivalent S2- atoms. All Ni–S bond lengths are 2.30 Å. In the third Ni+1.78+ site, Ni+1.78+ is bonded in a square co-planar geometry to four S2- atoms. There are two shorter (2.23 Å) and two longer (2.27 Å) Ni–S bond lengths. Bi1+ is bonded in a rectangular see-saw-like geometry to four equivalent S2- atoms. All Bi–S bond lengths are 2.80 Å. As3- is bonded in a body-centered cubic geometry to eight equivalent Ni+1.78+ atoms. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to four Ni+1.78+ and one Bi1+ atom. In the second S2- site, S2- is bonded in a 5-coordinate geometry to five Ni+1.78+ atoms.