Materials Data on Sr5Nb4O15 by Materials Project
Sr5Nb4O15 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. there are six inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with nine SrO12 cuboctahedra, faces with three SrO12 cuboctahedra, and faces with seven NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.58–3.05 Å. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with nine SrO12 cuboctahedra, faces with three SrO12 cuboctahedra, and faces with seven NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.58–3.07 Å. In the third Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.55–2.98 Å. In the fourth Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with six SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.77–2.87 Å. In the fifth Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.54–3.21 Å. In the sixth Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with six SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.77–2.88 Å. There are four inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with three NbO6 octahedra and faces with four SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 8–12°. There are a spread of Nb–O bond distances ranging from 1.88–2.24 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with seven SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Nb–O bond distances ranging from 1.96–2.07 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with three NbO6 octahedra and faces with four SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 7–12°. There are a spread of Nb–O bond distances ranging from 1.88–2.23 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with seven SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Nb–O bond distances ranging from 1.96–2.07 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to four Sr2+ and one Nb5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to four Sr2+ and one Nb5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to four Sr2+ and one Nb5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two Nb5+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two Nb5+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to four Sr2+ and one Nb5+ atom. In the tenth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two equivalent Nb5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two equivalent Nb5+ atoms.