Materials Data on Sr5Nb4O15 by Materials Project

Sr5Nb4O15 crystallizes in the trigonal P-3c1 space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 12-coordinate geometry to six O2- atoms. There are three shorter (2.61 Å) and three longer (2.62 Å) Sr–O bond lengths. In the second Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. There are three shorter (2.57 Å) and three longer (2.60 Å) Sr–O bond lengths. In the third Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with six equivalent SrO12 cuboctahedra and faces with eight NbO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.62–3.12 Å. There are two 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 three equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 14–18°. There are three shorter (1.97 Å) and three longer (2.08 Å) Nb–O bond lengths. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 octahedra that share corners with three equivalent NbO6 octahedra and a faceface with one SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 18°. There are three shorter (1.89 Å) and three longer (2.22 Å) Nb–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one Nb5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+ and two Nb5+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Sr2+ and two equivalent Nb5+ atoms.