Materials Data on CuGe5Pb3O14 by Materials Project
CuPb3Ge5O14 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Cu2+ is bonded to six O2- atoms to form distorted CuO6 octahedra that share corners with two equivalent GeO4 tetrahedra and edges with two equivalent GeO6 octahedra. There are a spread of Cu–O bond distances ranging from 1.94–2.55 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a 8-coordinate geometry to seven O2- atoms. There are a spread of Pb–O bond distances ranging from 2.31–3.17 Å. In the second 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 2.54–2.67 Å. There are three inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share a cornercorner with one CuO6 octahedra and a cornercorner with one GeO6 octahedra. The corner-sharing octahedra tilt angles range from 40–68°. There are a spread of Ge–O bond distances ranging from 1.74–1.82 Å. In the second Ge4+ site, Ge4+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Ge–O bond distances ranging from 1.78–2.41 Å. In the third Ge4+ site, Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with two equivalent GeO4 tetrahedra and edges with two equivalent CuO6 octahedra. There are a spread of Ge–O bond distances ranging from 1.88–1.99 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three Pb2+ and one Ge4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Pb2+ and two Ge4+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Pb2+ and two Ge4+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Cu2+, one Pb2+, and two Ge4+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Pb2+ and two Ge4+ atoms. In the sixth O2- site, O2- is bonded to one Cu2+, two Pb2+, and one Ge4+ atom to form distorted corner-sharing OCuGePb2 tetrahedra. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Cu2+, one Pb2+, and two Ge4+ atoms.