DOI: 10.17188/1739531
title: Materials Data on Nd15Si7Ni2 by Materials Project

description: Nd15Ni2Si7 crystallizes in the orthorhombic Fmm2 space group. The structure is three-dimensional. there are eleven inequivalent Nd sites. In the first Nd site, Nd is bonded to two Ni and four Si atoms to form distorted NdSi4Ni2 octahedra that share corners with four equivalent NdSi4Ni2 octahedra, corners with twelve NdSi4Ni trigonal bipyramids, and faces with four NdSi4Ni trigonal bipyramids. The corner-sharing octahedra tilt angles range from 55–56°. There are one shorter (3.07 Å) and one longer (3.09 Å) Nd–Ni bond lengths. There are a spread of Nd–Si bond distances ranging from 3.13–3.47 Å. In the second Nd site, Nd is bonded in a 6-coordinate geometry to one Ni and five Si atoms. The Nd–Ni bond length is 3.03 Å. There are a spread of Nd–Si bond distances ranging from 3.14–3.50 Å. In the third Nd site, Nd is bonded to one Ni and four Si atoms to form distorted NdSi4Ni trigonal bipyramids that share corners with two equivalent NdSi4Ni2 octahedra, corners with eight NdSi4Ni trigonal bipyramids, edges with seven NdSi5 trigonal bipyramids, and a faceface with one NdSi4Ni trigonal bipyramid. The corner-sharing octahedral tilt angles are 63°. The Nd–Ni bond length is 3.20 Å. There are two shorter (3.10 Å) and two longer (3.19 Å) Nd–Si bond lengths. In the fourth Nd site, Nd is bonded to one Ni and four Si atoms to form distorted NdSi4Ni trigonal bipyramids that share corners with two equivalent NdSi4Ni2 octahedra, corners with eight NdSi4Ni trigonal bipyramids, edges with three NdSi5 trigonal bipyramids, faces with two equivalent NdSi4Ni2 octahedra, and a faceface with one NdSi4Ni trigonal bipyramid. The corner-sharing octahedral tilt angles are 42°. The Nd–Ni bond length is 3.06 Å. There are two shorter (3.09 Å) and two longer (3.18 Å) Nd–Si bond lengths. In the fifth Nd site, Nd is bonded to one Ni and four Si atoms to form distorted NdSi4Ni trigonal bipyramids that share corners with twelve NdSi4Ni trigonal bipyramids, edges with seven NdSi5 trigonal bipyramids, and a faceface with one NdSi4Ni trigonal bipyramid. The Nd–Ni bond length is 3.17 Å. There are two shorter (3.09 Å) and two longer (3.19 Å) Nd–Si bond lengths. In the sixth Nd site, Nd is bonded to five Si atoms to form distorted NdSi5 trigonal bipyramids that share corners with two equivalent NdSi4Ni2 octahedra, corners with eight NdSi4Ni trigonal bipyramids, edges with seven NdSi4Ni trigonal bipyramids, and a faceface with one NdSi5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 64°. There are a spread of Nd–Si bond distances ranging from 3.08–3.20 Å. In the seventh Nd site, Nd is bonded to one Ni and four Si atoms to form distorted NdSi4Ni trigonal bipyramids that share corners with two equivalent NdSi4Ni2 octahedra, corners with eight NdSi4Ni trigonal bipyramids, edges with three NdSi4Ni trigonal bipyramids, faces with two equivalent NdSi4Ni2 octahedra, and a faceface with one NdSi4Ni trigonal bipyramid. The corner-sharing octahedral tilt angles are 42°. The Nd–Ni bond length is 3.05 Å. There are two shorter (3.08 Å) and two longer (3.19 Å) Nd–Si bond lengths. In the eighth Nd site, Nd is bonded to five Si atoms to form distorted NdSi5 trigonal bipyramids that share corners with twelve NdSi4Ni trigonal bipyramids, edges with seven NdSi4Ni trigonal bipyramids, and a faceface with one NdSi5 trigonal bipyramid. There are three shorter (3.07 Å) and two longer (3.19 Å) Nd–Si bond lengths. In the ninth Nd site, Nd is bonded to one Ni and four Si atoms to form distorted NdSi4Ni trigonal bipyramids that share corners with two equivalent NdSi4Ni2 octahedra, corners with ten NdSi4Ni trigonal bipyramids, edges with six NdSi4Ni trigonal bipyramids, and a faceface with one NdSi4Ni trigonal bipyramid. The corner-sharing octahedral tilt angles are 64°. The Nd–Ni bond length is 3.05 Å. There are a spread of Nd–Si bond distances ranging from 3.07–3.25 Å. In the tenth Nd site, Nd is bonded in a 5-coordinate geometry to two Ni and three Si atoms. There are one shorter (2.97 Å) and one longer (2.98 Å) Nd–Ni bond lengths. There are a spread of Nd–Si bond distances ranging from 3.07–3.31 Å. In the eleventh Nd site, Nd is bonded to one Ni and four Si atoms to form a mixture of distorted face, edge, and corner-sharing NdSi4Ni trigonal bipyramids. The Nd–Ni bond length is 3.02 Å. There are a spread of Nd–Si bond distances ranging from 3.06–3.26 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded in a 9-coordinate geometry to eight Nd and one Si atom. The Ni–Si bond length is 2.49 Å. In the second Ni site, Ni is bonded in a 9-coordinate geometry to eight Nd and one Ni atom. The Ni–Ni bond length is 2.67 Å. In the third Ni site, Ni is bonded in a 9-coordinate geometry to eight Nd and one Ni atom. There are five inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to eight Nd and one Si atom. The Si–Si bond length is 2.50 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to eight Nd and one Si atom. The Si–Si bond length is 2.50 Å. In the third Si site, Si is bonded in a 10-coordinate geometry to ten Nd atoms. In the fourth Si site, Si is bonded in a 10-coordinate geometry to ten Nd atoms. In the fifth Si site, Si is bonded in a 9-coordinate geometry to eight Nd and one Ni atom.