DOI: 10.17188/1281238
title: Materials Data on BaNb8O14 by Materials Project

description: BaNb8O14 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Ba2+ is bonded in a 11-coordinate geometry to eleven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.76–3.43 Å. There are eight inequivalent Nb+3.25+ sites. In the first Nb+3.25+ site, Nb+3.25+ is bonded to five O2- atoms to form distorted NbO5 square pyramids that share corners with four NbO5 square pyramids and edges with two equivalent NbO6 octahedra. There are a spread of Nb–O bond distances ranging from 2.06–2.44 Å. In the second Nb+3.25+ site, Nb+3.25+ is bonded to six O2- atoms to form NbO6 octahedra that share a cornercorner with one NbO6 octahedra, corners with four NbO5 square pyramids, and edges with two NbO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nb–O bond distances ranging from 1.96–2.18 Å. In the third Nb+3.25+ site, Nb+3.25+ is bonded in a see-saw-like geometry to four O2- atoms. There are one shorter (2.00 Å) and three longer (2.12 Å) Nb–O bond lengths. In the fourth Nb+3.25+ site, Nb+3.25+ is bonded to five O2- atoms to form NbO5 square pyramids that share a cornercorner with one NbO6 octahedra, corners with five NbO5 square pyramids, an edgeedge with one NbO6 octahedra, and an edgeedge with one NbO5 square pyramid. The corner-sharing octahedral tilt angles are 45°. There are a spread of Nb–O bond distances ranging from 2.07–2.18 Å. In the fifth Nb+3.25+ site, Nb+3.25+ is bonded to five O2- atoms to form distorted NbO5 square pyramids that share corners with two equivalent NbO6 octahedra, corners with five NbO5 square pyramids, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 45–50°. There are a spread of Nb–O bond distances ranging from 2.09–2.56 Å. In the sixth Nb+3.25+ site, Nb+3.25+ is bonded to five O2- atoms to form NbO5 square pyramids that share a cornercorner with one NbO6 octahedra, corners with four NbO5 square pyramids, an edgeedge with one NbO6 octahedra, and an edgeedge with one NbO5 square pyramid. The corner-sharing octahedral tilt angles are 41°. There are a spread of Nb–O bond distances ranging from 2.06–2.19 Å. In the seventh Nb+3.25+ site, Nb+3.25+ is bonded to five O2- atoms to form NbO5 square pyramids that share corners with two equivalent NbO6 octahedra, corners with six NbO5 square pyramids, and an edgeedge with one NbO6 octahedra. The corner-sharing octahedra tilt angles range from 5–45°. There are a spread of Nb–O bond distances ranging from 2.09–2.24 Å. In the eighth Nb+3.25+ site, Nb+3.25+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. There are a spread of Nb–O bond distances ranging from 1.85–2.17 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to one Ba2+ and three Nb+3.25+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Nb+3.25+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Nb+3.25+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Nb+3.25+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+ and two Nb+3.25+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to three Nb+3.25+ atoms. In the seventh O2- site, O2- is bonded in a distorted T-shaped geometry to one Ba2+ and three Nb+3.25+ atoms. In the eighth O2- site, O2- is bonded in a linear geometry to two equivalent Ba2+ and two equivalent Nb+3.25+ atoms. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to three Nb+3.25+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Nb+3.25+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Nb+3.25+ atoms. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+ and three Nb+3.25+ atoms. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Nb+3.25+ atoms. In the fourteenth O2- site, O2- is bonded in a square co-planar geometry to four Nb+3.25+ atoms. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three Nb+3.25+ atoms.