DOI: 10.17188/1710058
title: Materials Data on Ti4Si4Ni by Materials Project

description: Ti4NiSi4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are seven inequivalent Ti+3.50+ sites. In the first Ti+3.50+ site, Ti+3.50+ is bonded in a 8-coordinate geometry to eight Si4- atoms. There are a spread of Ti–Si bond distances ranging from 2.62–2.78 Å. In the second Ti+3.50+ site, Ti+3.50+ is bonded to seven Si4- atoms to form TiSi7 pentagonal bipyramids that share corners with four equivalent TiSi6 octahedra, corners with seven TiSi7 pentagonal bipyramids, a cornercorner with one TiSi6 pentagonal pyramid, corners with four equivalent NiSi5 trigonal bipyramids, edges with two equivalent TiSi7 pentagonal bipyramids, faces with four equivalent TiSi6 octahedra, faces with three TiSi7 pentagonal bipyramids, and faces with two equivalent TiSi6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 56°. There are a spread of Ti–Si bond distances ranging from 2.55–2.85 Å. In the third Ti+3.50+ site, Ti+3.50+ is bonded to seven Si4- atoms to form TiSi7 pentagonal bipyramids that share corners with four equivalent TiSi6 octahedra, corners with five TiSi7 pentagonal bipyramids, corners with two equivalent TiSi6 pentagonal pyramids, corners with four equivalent NiSi5 trigonal bipyramids, edges with two equivalent TiSi6 pentagonal pyramids, faces with two equivalent TiSi6 octahedra, faces with five TiSi7 pentagonal bipyramids, and faces with two equivalent NiSi5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 36–54°. There are a spread of Ti–Si bond distances ranging from 2.54–2.80 Å. In the fourth Ti+3.50+ site, Ti+3.50+ is bonded to seven Si4- atoms to form TiSi7 pentagonal bipyramids that share corners with six equivalent TiSi6 octahedra, corners with four TiSi7 pentagonal bipyramids, a cornercorner with one TiSi6 pentagonal pyramid, corners with two equivalent NiSi5 trigonal bipyramids, edges with two equivalent TiSi7 pentagonal bipyramids, faces with two equivalent TiSi6 octahedra, faces with five TiSi7 pentagonal bipyramids, a faceface with one TiSi6 pentagonal pyramid, and faces with two equivalent NiSi5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 34–55°. There are a spread of Ti–Si bond distances ranging from 2.65–2.82 Å. In the fifth Ti+3.50+ site, Ti+3.50+ is bonded to six Si4- atoms to form distorted TiSi6 pentagonal pyramids that share corners with four equivalent TiSi6 octahedra, corners with five TiSi7 pentagonal bipyramids, corners with two equivalent TiSi6 pentagonal pyramids, corners with two equivalent NiSi5 trigonal bipyramids, edges with three TiSi7 pentagonal bipyramids, edges with two equivalent NiSi5 trigonal bipyramids, faces with two equivalent TiSi6 octahedra, and faces with three TiSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 42–53°. There are a spread of Ti–Si bond distances ranging from 2.54–2.78 Å. In the sixth Ti+3.50+ site, Ti+3.50+ is bonded to seven Si4- atoms to form TiSi7 pentagonal bipyramids that share corners with two equivalent TiSi6 octahedra, corners with six TiSi7 pentagonal bipyramids, a cornercorner with one TiSi6 pentagonal pyramid, corners with four equivalent NiSi5 trigonal bipyramids, edges with two equivalent TiSi7 pentagonal bipyramids, an edgeedge with one TiSi6 pentagonal pyramid, faces with two equivalent TiSi6 octahedra, faces with three TiSi7 pentagonal bipyramids, and faces with two equivalent NiSi5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 53°. There are a spread of Ti–Si bond distances ranging from 2.51–2.81 Å. In the seventh Ti+3.50+ site, Ti+3.50+ is bonded to six Si4- atoms to form distorted TiSi6 octahedra that share corners with two equivalent TiSi6 octahedra, corners with eight TiSi7 pentagonal bipyramids, corners with two equivalent TiSi6 pentagonal pyramids, corners with four equivalent NiSi5 trigonal bipyramids, an edgeedge with one TiSi6 octahedra, edges with two equivalent NiSi5 trigonal bipyramids, faces with two equivalent TiSi6 octahedra, faces with five TiSi7 pentagonal bipyramids, and a faceface with one TiSi6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 33°. There are a spread of Ti–Si bond distances ranging from 2.51–2.64 Å. Ni2+ is bonded to five Si4- atoms to form distorted NiSi5 trigonal bipyramids that share corners with four equivalent TiSi6 octahedra, corners with seven TiSi7 pentagonal bipyramids, a cornercorner with one TiSi6 pentagonal pyramid, edges with two equivalent TiSi6 octahedra, an edgeedge with one TiSi6 pentagonal pyramid, an edgeedge with one NiSi5 trigonal bipyramid, faces with three TiSi7 pentagonal bipyramids, and a faceface with one NiSi5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 31–42°. There are a spread of Ni–Si bond distances ranging from 2.30–2.34 Å. There are seven inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to four Ti+3.50+, two equivalent Ni2+, and three Si4- atoms. There are one shorter (2.42 Å) and two longer (2.52 Å) Si–Si bond lengths. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to seven Ti+3.50+ and two equivalent Ni2+ atoms. In the third Si4- site, Si4- is bonded in a 9-coordinate geometry to six Ti+3.50+, two equivalent Ni2+, and one Si4- atom. In the fourth Si4- site, Si4- is bonded in a 9-coordinate geometry to seven Ti+3.50+ and two equivalent Ni2+ atoms. In the fifth Si4- site, Si4- is bonded in a 9-coordinate geometry to nine Ti+3.50+ atoms. In the sixth Si4- site, Si4- is bonded in a 9-coordinate geometry to seven Ti+3.50+ and two equivalent Ni2+ atoms. In the seventh Si4- site, Si4- is bonded in a 10-coordinate geometry to seven Ti+3.50+ and three Si4- atoms. There are one shorter (2.50 Å) and one longer (2.60 Å) Si–Si bond lengths.