Materials Data on Sr5Nb5O16 by Materials Project
Sr5Nb5O16 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are five inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.51–2.74 Å. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with two equivalent SrO12 cuboctahedra, faces with two equivalent SrO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.64–3.04 Å. In the third Sr2+ site, Sr2+ is bonded in a 11-coordinate geometry to eleven O2- atoms. There are a spread of Sr–O bond distances ranging from 2.62–3.03 Å. In the fourth Sr2+ site, Sr2+ is bonded in a 12-coordinate geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.56–3.00 Å. In the fifth 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 2.49–3.01 Å. There are five inequivalent Nb+4.40+ sites. In the first Nb+4.40+ site, Nb+4.40+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 7–30°. There are a spread of Nb–O bond distances ranging from 1.87–2.27 Å. In the second Nb+4.40+ site, Nb+4.40+ 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 7–30°. There are a spread of Nb–O bond distances ranging from 1.90–2.16 Å. In the third Nb+4.40+ site, Nb+4.40+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–20°. There are a spread of Nb–O bond distances ranging from 2.02–2.06 Å. In the fourth Nb+4.40+ site, Nb+4.40+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 1.89–2.15 Å. In the fifth Nb+4.40+ site, Nb+4.40+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with four NbO6 octahedra and faces with two equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 8–14°. There are a spread of Nb–O bond distances ranging from 1.97–2.16 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three equivalent Sr2+ and one Nb+4.40+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two Nb+4.40+ atoms. In the third O2- site, O2- is bonded to three equivalent Sr2+ and one Nb+4.40+ atom to form corner-sharing OSr3Nb tetrahedra. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Sr2+ and two Nb+4.40+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two Nb+4.40+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two Nb+4.40+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two Nb+4.40+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Sr2+ and two Nb+4.40+ atoms. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two Nb+4.40+ atoms. In the tenth O2- site, O2- is bonded to three equivalent Sr2+ and one Nb+4.40+ atom to form corner-sharing OSr3Nb tetrahedra. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+ and two Nb+4.40+ atoms. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Sr2+ and one Nb+4.40+ atom. In the thirteenth O2- site, O2- is bonded in a distorted linear geometry to three Sr2+ and two equivalent Nb+4.40+ atoms. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two equivalent Nb+4.40+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two equivalent Nb+4.40+ atoms. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Sr2+ and two equivalent Nb+4.40+ atoms.