Materials Data on SiNi2 by Materials Project

Abstract

Ni2Si crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to five equivalent Si4- atoms to form NiSi5 trigonal bipyramids that share corners with twelve equivalent NiSi6 octahedra, corners with eight equivalent NiSi5 trigonal bipyramids, edges with six equivalent NiSi5 trigonal bipyramids, and faces with six equivalent NiSi6 octahedra. The corner-sharing octahedra tilt angles range from 29–61°. There are three shorter (2.25 Å) and two longer (2.49 Å) Ni–Si bond lengths. In the second Ni2+ site, Ni2+ is bonded to six equivalent Si4- atoms to form NiSi6 octahedra that share corners with twelve equivalent NiSi6 octahedra, corners with twelve equivalent NiSi5 trigonal bipyramids, edges with six equivalent NiSi6 octahedra, faces with two equivalent NiSi6 octahedra, and faces with six equivalent NiSi5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 52°. All Ni–Si bond lengths are 2.57 Å. Si4- is bonded in a 11-coordinate geometry to eleven Ni2+ atoms.