Materials Data on Ba3Nb16O23 by Materials Project
Ba3Nb16O23 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with two equivalent BaO12 cuboctahedra, corners with four equivalent NbO5 square pyramids, faces with three BaO12 cuboctahedra, and faces with eight NbO5 square pyramids. There are a spread of Ba–O bond distances ranging from 2.93–2.98 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, faces with four BaO12 cuboctahedra, and faces with eight equivalent NbO5 square pyramids. There are a spread of Ba–O bond distances ranging from 2.92–3.04 Å. There are five inequivalent Nb+2.50+ sites. In the first Nb+2.50+ site, Nb+2.50+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent BaO12 cuboctahedra, corners with five NbO5 square pyramids, an edgeedge with one NbO5 square pyramid, and faces with two equivalent BaO12 cuboctahedra. There are four shorter (2.11 Å) and one longer (2.24 Å) Nb–O bond lengths. In the second Nb+2.50+ site, Nb+2.50+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with six NbO5 square pyramids and faces with four BaO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 2.09–2.15 Å. In the third Nb+2.50+ site, Nb+2.50+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 2.11–2.15 Å. In the fourth Nb+2.50+ site, Nb+2.50+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 2.08–2.16 Å. In the fifth Nb+2.50+ site, Nb+2.50+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 2.11–2.18 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four Ba2+ and two equivalent Nb+2.50+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.50+ atoms. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+2.50+ atoms. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.50+ atoms. In the fifth O2- site, O2- is bonded in a distorted T-shaped geometry to two Ba2+ and three Nb+2.50+ atoms. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.50+ atoms. In the seventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Nb+2.50+ atoms. In the eighth O2- site, O2- is bonded in a square co-planar geometry to four Nb+2.50+ atoms. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Nb+2.50+ atoms.