Materials Data on Sr5Nb5O17 by Materials Project

Abstract

Sr5Nb5O17 crystallizes in the orthorhombic Pnn2 space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.49–2.97 Å. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with ten SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.69–3.05 Å. In the third Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with seven SrO12 cuboctahedra, faces with four SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.55–3.13 Å. There are three inequivalent Nb+4.80+ sites. In the first Nb+4.80+ site, Nb+4.80+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–16°. There are a spread of Nb–O bond distances ranging from 2.00–2.06 Å. In the second Nb+4.80+ site, Nb+4.80+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with four NbO6 octahedra and faces with two equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 10–32°. There are a spread of Nb–O bond distances ranging from 1.86–2.33 Å. In the third Nb+4.80+ site, Nb+4.80+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with six SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 8–32°. There are a spread of Nb–O bond distances ranging from 1.87–2.22 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two Nb+4.80+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Sr2+ and two Nb+4.80+ atoms. In the third O2- site, O2- is bonded to three equivalent Sr2+ and one Nb+4.80+ atom to form distorted corner-sharing OSr3Nb tetrahedra. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Sr2+ and two equivalent Nb+4.80+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two equivalent Nb+4.80+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to four Sr2+ and two Nb+4.80+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two Nb+4.80+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two equivalent Nb+4.80+ atoms. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three equivalent Sr2+ and one Nb+4.80+ atom.