Materials Data on NaSr2Nb5O15 by Materials Project

Abstract

NaSr2Nb5O15 crystallizes in the orthorhombic Cmm2 space group. The structure is three-dimensional. Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are one shorter (2.55 Å) and two longer (2.70 Å) Na–O bond lengths. There are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 4-coordinate geometry to eleven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.48–3.20 Å. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share faces with two equivalent SrO12 cuboctahedra and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.65–2.96 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 six NbO6 octahedra and faces with two equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 10–47°. There are a spread of Nb–O bond distances ranging from 1.88–2.22 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 two equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 7–39°. There are a spread of Nb–O bond distances ranging from 1.86–2.22 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 0–34°. There are a spread of Nb–O bond distances ranging from 1.82–2.26 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 0–38°. There are a spread of Nb–O bond distances ranging from 1.84–2.24 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two equivalent Nb5+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two equivalent Nb5+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Sr2+ and two equivalent Nb5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+ and two equivalent Nb5+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Sr2+ and two Nb5+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and two Nb5+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Sr2+ and two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Nb5+ atoms. In the tenth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Sr2+ and two equivalent Nb5+ atoms.