Materials Data on Ta2Pb2O7 by Materials Project
Pb2Ta2O7 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 2–19°. There are a spread of Ta–O bond distances ranging from 1.88–2.23 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form distorted corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 2–19°. There are a spread of Ta–O bond distances ranging from 1.85–2.35 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Pb–O bond distances ranging from 2.49–2.59 Å. In the second Pb2+ site, Pb2+ is bonded in a 11-coordinate geometry to eleven O2- atoms. There are a spread of Pb–O bond distances ranging from 2.55–3.09 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two Ta5+ and two equivalent Pb2+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ta5+ and four equivalent Pb2+ atoms. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Ta5+ and three equivalent Pb2+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two Ta5+ and two equivalent Pb2+ atoms. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Ta5+ and three equivalent Pb2+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one Pb2+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and two equivalent Pb2+ atoms.