DOI: 10.17188/1748440
title: Materials Data on BaNb6Bi6Pb2O27 by Materials Project

description: BaNb6Pb2Bi6O27 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, and faces with eight equivalent NbO6 octahedra. There are four shorter (2.80 Å) and eight longer (2.84 Å) Ba–O bond lengths. There are three inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five equivalent NbO6 octahedra and faces with four equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Nb–O bond distances ranging from 1.90–2.26 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five NbO6 octahedra and faces with four equivalent PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Nb–O bond distances ranging from 1.91–2.23 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five NbO6 octahedra and faces with four equivalent PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Nb–O bond distances ranging from 1.91–2.23 Å. Pb2+ is bonded to twelve O2- atoms to form PbO12 cuboctahedra that share corners with four equivalent PbO12 cuboctahedra, faces with four equivalent PbO12 cuboctahedra, and faces with eight NbO6 octahedra. There are four shorter (2.80 Å) and eight longer (2.81 Å) Pb–O bond lengths. There are three inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are four shorter (2.33 Å) and four longer (2.96 Å) Bi–O bond lengths. In the second Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are four shorter (2.34 Å) and four longer (2.97 Å) Bi–O bond lengths. In the third Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are four shorter (2.34 Å) and four longer (2.97 Å) Bi–O bond lengths. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Nb5+ and four equivalent Bi3+ atoms. In the second O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the third O2- site, O2- is bonded to four equivalent Bi3+ atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+ and two equivalent Nb5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Nb5+ and two equivalent Pb2+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to two Nb5+ and four equivalent Pb2+ atoms. In the seventh O2- site, O2- is bonded to four equivalent Ba2+ and two equivalent Nb5+ atoms to form a mixture of distorted corner and edge-sharing OBa4Nb2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the eighth O2- site, O2- is bonded in a single-bond geometry to one Nb5+ and four equivalent Bi3+ atoms. In the ninth O2- site, O2- is bonded in a single-bond geometry to one Nb5+ and four equivalent Bi3+ atoms.