Materials Data on BaNb4Bi4PbO18 by Materials Project

Abstract

BaNb4PbBi4O18 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the orthorhombic Amm2 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 PbO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.66–3.02 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 five NbO6 octahedra, faces with two equivalent BaO12 cuboctahedra, and faces with two equivalent PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 6–19°. There are a spread of Nb–O bond distances ranging from 1.90–2.19 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five NbO6 octahedra, faces with two equivalent BaO12 cuboctahedra, and faces with two equivalent PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–19°. There are a spread of Nb–O bond distances ranging from 1.91–2.19 Å. Pb2+ is bonded to twelve O2- atoms to form distorted PbO12 cuboctahedra that share corners with four equivalent PbO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.59–3.12 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Bi–O bond distances ranging from 2.25–2.46 Å. In the second Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.24–3.00 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Nb5+ and three Bi3+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Nb5+ and one Bi3+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ba2+, two equivalent Nb5+, and two equivalent Pb2+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, two equivalent Nb5+, and two equivalent Pb2+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to one Ba2+, two Nb5+, and one Pb2+ atom. In the sixth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Ba2+, two Nb5+, and one Pb2+ atom.