DOI: 10.17188/1682648
title: Materials Data on Nb4Fe3Si5 by Materials Project

description: Nb4Fe3Si5 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are twelve inequivalent Nb+2.75+ sites. In the first Nb+2.75+ site, Nb+2.75+ is bonded in a 6-coordinate geometry to six Si4- atoms. There are a spread of Nb–Si bond distances ranging from 2.60–2.96 Å. In the second Nb+2.75+ site, Nb+2.75+ is bonded in a 7-coordinate geometry to seven Si4- atoms. There are a spread of Nb–Si bond distances ranging from 2.72–2.92 Å. In the third Nb+2.75+ site, Nb+2.75+ is bonded in a 8-coordinate geometry to eight Si4- atoms. There are a spread of Nb–Si bond distances ranging from 2.75–2.98 Å. In the fourth Nb+2.75+ site, Nb+2.75+ is bonded in a 8-coordinate geometry to eight Si4- atoms. There are a spread of Nb–Si bond distances ranging from 2.80–2.97 Å. In the fifth Nb+2.75+ site, Nb+2.75+ is bonded to six Si4- atoms to form NbSi6 octahedra that share corners with two equivalent SiNb5FeSi6 cuboctahedra, corners with two equivalent NbSi6 octahedra, corners with two equivalent FeSi6 octahedra, corners with five NbSi7 pentagonal bipyramids, an edgeedge with one NbSi7 pentagonal bipyramid, and faces with five NbSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 37–59°. There are a spread of Nb–Si bond distances ranging from 2.72–2.84 Å. In the sixth Nb+2.75+ site, Nb+2.75+ is bonded to seven Si4- atoms to form distorted NbSi7 pentagonal bipyramids that share corners with two equivalent NbSi6 octahedra, corners with two equivalent FeSi6 octahedra, corners with four NbSi7 pentagonal bipyramids, corners with two equivalent FeSi4 tetrahedra, edges with four equivalent SiNb5FeSi6 cuboctahedra, an edgeedge with one NbSi7 pentagonal bipyramid, edges with two equivalent FeSi4 tetrahedra, and faces with four NbSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–49°. There are a spread of Nb–Si bond distances ranging from 2.66–2.81 Å. In the seventh Nb+2.75+ site, Nb+2.75+ is bonded to seven Si4- atoms to form NbSi7 pentagonal bipyramids that share corners with four equivalent FeSi6 octahedra, corners with eight NbSi7 pentagonal bipyramids, a faceface with one NbSi6 octahedra, faces with two equivalent FeSi6 octahedra, and faces with five NbSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 38–51°. There are a spread of Nb–Si bond distances ranging from 2.64–2.78 Å. In the eighth Nb+2.75+ site, Nb+2.75+ is bonded to seven Si4- atoms to form NbSi7 pentagonal bipyramids that share corners with two equivalent FeSi6 octahedra, corners with six NbSi7 pentagonal bipyramids, edges with three NbSi7 pentagonal bipyramids, faces with two equivalent NbSi6 octahedra, faces with two equivalent FeSi6 octahedra, and faces with four NbSi7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 50°. There are a spread of Nb–Si bond distances ranging from 2.66–2.90 Å. In the ninth Nb+2.75+ site, Nb+2.75+ is bonded to seven Si4- atoms to form NbSi7 pentagonal bipyramids that share corners with three equivalent NbSi6 octahedra, corners with four equivalent FeSi6 octahedra, corners with three NbSi7 pentagonal bipyramids, corners with two equivalent FeSi4 tetrahedra, edges with three NbSi7 pentagonal bipyramids, faces with two equivalent FeSi6 octahedra, and faces with six NbSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 31–51°. There are a spread of Nb–Si bond distances ranging from 2.66–2.80 Å. In the tenth Nb+2.75+ site, Nb+2.75+ is bonded to seven Si4- atoms to form distorted NbSi7 pentagonal bipyramids that share corners with six NbSi7 pentagonal bipyramids, edges with four equivalent SiNb5FeSi6 cuboctahedra, an edgeedge with one NbSi7 pentagonal bipyramid, faces with two equivalent NbSi6 octahedra, and faces with two NbSi7 pentagonal bipyramids. There are a spread of Nb–Si bond distances ranging from 2.69–2.80 Å. In the eleventh Nb+2.75+ site, Nb+2.75+ is bonded in a 6-coordinate geometry to seven Si4- atoms. There are a spread of Nb–Si bond distances ranging from 2.59–3.17 Å. In the twelfth Nb+2.75+ site, Nb+2.75+ is bonded to seven Si4- atoms to form NbSi7 pentagonal bipyramids that share corners with two equivalent SiNb5FeSi6 cuboctahedra, corners with two equivalent FeSi6 octahedra, corners with seven NbSi7 pentagonal bipyramids, corners with two equivalent FeSi4 tetrahedra, an edgeedge with one NbSi6 octahedra, faces with two equivalent FeSi6 octahedra, faces with five NbSi7 pentagonal bipyramids, and faces with two equivalent FeSi4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Nb–Si bond distances ranging from 2.60–2.82 Å. There are five inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four Si4- atoms to form distorted FeSi4 tetrahedra that share corners with four equivalent SiNb5FeSi6 cuboctahedra, corners with two equivalent FeSi6 octahedra, corners with three NbSi7 pentagonal bipyramids, an edgeedge with one FeSi6 octahedra, an edgeedge with one NbSi7 pentagonal bipyramid, edges with two equivalent FeSi4 tetrahedra, and a faceface with one NbSi7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 32–34°. There are a spread of Fe–Si bond distances ranging from 2.28–2.38 Å. In the second Fe3+ site, Fe3+ is bonded in a 5-coordinate geometry to five Si4- atoms. There are a spread of Fe–Si bond distances ranging from 2.35–2.45 Å. In the third Fe3+ site, Fe3+ is bonded to six Si4- atoms to form distorted FeSi6 octahedra that share a cornercorner with one NbSi6 octahedra, corners with seven NbSi7 pentagonal bipyramids, corners with two equivalent FeSi4 tetrahedra, an edgeedge with one FeSi4 tetrahedra, faces with two equivalent FeSi6 octahedra, and faces with four NbSi7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 37°. There are a spread of Fe–Si bond distances ranging from 2.42–2.48 Å. In the fourth Fe3+ site, Fe3+ is bonded in a distorted hexagonal planar geometry to six Si4- atoms. There are a spread of Fe–Si bond distances ranging from 2.27–2.38 Å. In the fifth Fe3+ site, Fe3+ is bonded in a trigonal non-coplanar geometry to three Si4- atoms. There are two shorter (2.31 Å) and one longer (2.42 Å) Fe–Si bond lengths. There are thirteen inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 12-coordinate geometry to seven Nb+2.75+, four Fe3+, and one Si4- atom. The Si–Si bond length is 2.52 Å. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to five Nb+2.75+ and four Fe3+ atoms. In the third Si4- site, Si4- is bonded in a 9-coordinate geometry to five Nb+2.75+ and four Fe3+ atoms. In the fourth Si4- site, Si4- is bonded in a 10-coordinate geometry to seven Nb+2.75+, one Fe3+, and two equivalent Si4- atoms. There are one shorter (2.47 Å) and one longer (2.48 Å) Si–Si bond lengths. In the fifth Si4- site, Si4- is bonded in a 9-coordinate geometry to five Nb+2.75+ and four Fe3+ atoms. In the sixth Si4- site, Si4- is bonded in a 9-coordinate geometry to five Nb+2.75+ and four Fe3+ atoms. In the seventh Si4- site, Si4- is bonded in a 12-coordinate geometry to six Nb+2.75+, two equivalent Fe3+, and four Si4- atoms. There are a spread of Si–Si bond distances ranging from 2.57–2.81 Å. In the eighth Si4- site, Si4- is bonded in a 12-coordinate geometry to six Nb+2.75+, three Fe3+, and three Si4- atoms. Both Si–Si bond lengths are 2.70 Å. In the ninth Si4- site, Si4- is bonded in a 9-coordinate geometry to five Nb+2.75+ and four Fe3+ atoms. In the tenth Si4- site, Si4- is bonded in a 9-coordinate geometry to four Nb+2.75+, four Fe3+, and one Si4- atom. In the eleventh Si4- site, Si4- is bonded in a 12-coordinate geometry to six Nb+2.75+, three Fe3+, and three Si4- atoms. There are two shorter (2.62 Å) and one longer (2.79 Å) Si–Si bond lengths. In the twelfth Si4- site, Si4- is bonded in a 12-coordinate geometry to six Nb+2.75+, two equivalent Fe3+, and four Si4- atoms. Both Si–Si bond lengths are 2.73 Å. In the thirteenth Si4- site, Si4- is bonded to five Nb+2.75+, one Fe3+, and six Si4- atoms to form distorted SiNb5FeSi6 cuboctahedra that share corners with two equivalent SiNb5FeSi6 cuboctahedra, a cornercorner with one NbSi6 octahedra, a cornercorner with one NbSi7 pentagonal bipyramid, corners with four equivalent FeSi4 tetrahedra, edges with four NbSi7 pentagonal bipyramids, and faces with two equivalent SiNb5FeSi6 cuboctahedra. The corner-sharing octahedral tilt angles are 68°. There are one shorter (2.30 Å) and one longer (2.65 Å) Si–Si bond lengths.