Materials Data on KSr2Nb5O15 by Materials Project
KSr2Nb5O15 crystallizes in the orthorhombic Cmm2 space group. The structure is three-dimensional. K1+ is bonded in a 4-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.84–3.22 Å. There are two inequivalent Sr2+ sites. In the first 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 2.71–2.88 Å. In the second Sr2+ site, Sr2+ is bonded in a 4-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.59–3.11 Å. There are four inequivalent Nb5+ sites. In the first 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 11–47°. There are a spread of Nb–O bond distances ranging from 1.90–2.18 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 8–38°. There are a spread of Nb–O bond distances ranging from 1.88–2.18 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of Nb–O bond distances ranging from 1.83–2.23 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form 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 1.85–2.21 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ 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 equivalent Sr2+ and two Nb5+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ and two Nb5+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two Sr2+ and two equivalent Nb5+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Sr2+, and two equivalent Nb5+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent 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 K1+ and 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.