DOI: 10.17188/1708207
title: Materials Data on Ni11As8 by Materials Project

description: Ni11As8 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are six inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to five As+2.75- atoms to form distorted NiAs5 trigonal bipyramids that share a cornercorner with one NiAs6 octahedra, corners with three equivalent NiAs5 square pyramids, corners with eleven NiAs5 trigonal bipyramids, an edgeedge with one NiAs5 square pyramid, edges with five NiAs5 trigonal bipyramids, and a faceface with one NiAs6 octahedra. The corner-sharing octahedral tilt angles are 63°. There are a spread of Ni–As bond distances ranging from 2.31–2.51 Å. In the second Ni2+ site, Ni2+ is bonded to five As+2.75- atoms to form distorted NiAs5 trigonal bipyramids that share corners with three equivalent NiAs6 octahedra, corners with three equivalent NiAs5 square pyramids, corners with eleven NiAs5 trigonal bipyramids, edges with five NiAs5 trigonal bipyramids, and a faceface with one NiAs5 square pyramid. The corner-sharing octahedra tilt angles range from 53–63°. There are a spread of Ni–As bond distances ranging from 2.39–2.45 Å. In the third Ni2+ site, Ni2+ is bonded to five As+2.75- atoms to form distorted NiAs5 trigonal bipyramids that share corners with three equivalent NiAs6 octahedra, corners with three equivalent NiAs5 square pyramids, corners with eleven NiAs5 trigonal bipyramids, edges with five NiAs5 trigonal bipyramids, and a faceface with one NiAs5 square pyramid. The corner-sharing octahedra tilt angles range from 53–63°. There are a spread of Ni–As bond distances ranging from 2.39–2.47 Å. In the fourth Ni2+ site, Ni2+ is bonded to five As+2.75- atoms to form NiAs5 square pyramids that share corners with four equivalent NiAs5 square pyramids, corners with twelve NiAs5 trigonal bipyramids, edges with two equivalent NiAs6 octahedra, edges with two NiAs5 trigonal bipyramids, and faces with two NiAs5 trigonal bipyramids. There are a spread of Ni–As bond distances ranging from 2.35–2.49 Å. In the fifth Ni2+ site, Ni2+ is bonded to five As+2.75- atoms to form distorted NiAs5 trigonal bipyramids that share a cornercorner with one NiAs6 octahedra, corners with three equivalent NiAs5 square pyramids, corners with eleven NiAs5 trigonal bipyramids, an edgeedge with one NiAs5 square pyramid, edges with five NiAs5 trigonal bipyramids, and a faceface with one NiAs6 octahedra. The corner-sharing octahedral tilt angles are 62°. There are a spread of Ni–As bond distances ranging from 2.31–2.50 Å. In the sixth Ni2+ site, Ni2+ is bonded to six As+2.75- atoms to form a mixture of corner, edge, and face-sharing NiAs6 octahedra. There are a spread of Ni–As bond distances ranging from 2.48–2.65 Å. There are five inequivalent As+2.75- sites. In the first As+2.75- site, As+2.75- is bonded in a 7-coordinate geometry to seven Ni2+ atoms. In the second As+2.75- site, As+2.75- is bonded in a 7-coordinate geometry to seven Ni2+ atoms. In the third As+2.75- site, As+2.75- is bonded in a distorted hexagonal pyramidal geometry to seven Ni2+ atoms. In the fourth As+2.75- site, As+2.75- is bonded in a 7-coordinate geometry to seven Ni2+ atoms. In the fifth As+2.75- site, As+2.75- is bonded in a 7-coordinate geometry to seven Ni2+ atoms.