Materials Data on Ba4Nb25O40 by Materials Project

Ba4Nb25O40 crystallizes in the monoclinic P2/m 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 eight NbO5 square pyramids, faces with two equivalent BaO12 cuboctahedra, and faces with eight NbO5 square pyramids. There are a spread of Ba–O bond distances ranging from 2.89–3.00 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with eight NbO5 square pyramids, faces with two equivalent BaO12 cuboctahedra, and faces with eight NbO5 square pyramids. There are a spread of Ba–O bond distances ranging from 2.94–2.97 Å. There are thirteen inequivalent Nb+2.88+ sites. In the first Nb+2.88+ site, Nb+2.88+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. All Nb–O bond lengths are 2.12 Å. In the second Nb+2.88+ site, Nb+2.88+ is bonded in a square co-planar geometry to four O2- atoms. All Nb–O bond lengths are 2.12 Å. In the third Nb+2.88+ site, Nb+2.88+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Nb–O bond distances ranging from 2.10–2.13 Å. In the fourth Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent BaO12 cuboctahedra, corners with six NbO5 square pyramids, an edgeedge with one NbO5 square pyramid, and faces with two equivalent BaO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 2.08–2.20 Å. In the fifth Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent BaO12 cuboctahedra, corners with six NbO5 square pyramids, an edgeedge with one NbO5 square pyramid, and faces with two equivalent BaO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 2.08–2.20 Å. In the sixth Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent BaO12 cuboctahedra, corners with six NbO5 square pyramids, an edgeedge with one NbO5 square pyramid, and faces with two equivalent BaO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 2.08–2.20 Å. In the seventh Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with six NbO5 square pyramids, an edgeedge with one NbO5 square pyramid, and faces with two equivalent BaO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 2.08–2.18 Å. In the eighth Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent BaO12 cuboctahedra, corners with six NbO5 square pyramids, and an edgeedge with one NbO5 square pyramid. There are a spread of Nb–O bond distances ranging from 1.98–2.24 Å. In the ninth Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent BaO12 cuboctahedra, corners with six NbO5 square pyramids, an edgeedge with one NbO5 square pyramid, and faces with two equivalent BaO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 2.08–2.17 Å. In the tenth Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent BaO12 cuboctahedra, corners with six NbO5 square pyramids, an edgeedge with one NbO5 square pyramid, and faces with two equivalent BaO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 2.08–2.20 Å. In the eleventh Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent BaO12 cuboctahedra, corners with six NbO5 square pyramids, an edgeedge with one NbO5 square pyramid, and faces with two equivalent BaO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 2.08–2.20 Å. In the twelfth Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent BaO12 cuboctahedra, corners with six NbO5 square pyramids, an edgeedge with one NbO5 square pyramid, and faces with two equivalent BaO12 cuboctahedra. There are a spread of Nb–O bond distances ranging from 2.08–2.21 Å. In the thirteenth Nb+2.88+ site, Nb+2.88+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NbO5 square pyramids. There are a spread of Nb–O bond distances ranging from 2.04–2.16 Å. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.88+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.88+ atoms. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.88+ atoms. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.88+ atoms. In the fifth O2- site, O2- is bonded in a T-shaped geometry to three Nb+2.88+ atoms. In the sixth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.88+ atoms. In the seventh O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.88+ atoms. In the eighth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.88+ atoms. In the ninth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three Nb+2.88+ atoms. In the tenth O2- site, O2- is bonded in a T-shaped geometry to three Nb+2.88+ atoms. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+2.88+ atoms. In the twelfth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+2.88+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+2.88+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+2.88+ atoms. In the fifteenth O2- site, O2- is bonded in a T-shaped geometry to three Nb+2.88+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+2.88+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+2.88+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+2.88+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+2.88+ atoms. In the twentieth O2- site, O2- is bonded in a T-shaped geometry to three Nb+2.88+ atoms.