Materials Data on SrGe12Pb2O27 by Materials Project
SrPb2Ge12O27 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Sr2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.65–3.22 Å. Pb2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Pb–O bond distances ranging from 2.67–3.24 Å. There are seven inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent GeO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 62°. There are a spread of Ge–O bond distances ranging from 1.78–1.81 Å. In the second Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent GeO6 octahedra and corners with two equivalent GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 62°. There is two shorter (1.79 Å) and two longer (1.81 Å) Ge–O bond length. In the third Ge4+ site, Ge4+ is bonded to six O2- atoms to form corner-sharing GeO6 octahedra. There is four shorter (1.93 Å) and two longer (1.94 Å) Ge–O bond length. In the fourth Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent GeO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–61°. There are a spread of Ge–O bond distances ranging from 1.77–1.80 Å. In the fifth Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent GeO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–61°. There are a spread of Ge–O bond distances ranging from 1.76–1.80 Å. In the sixth Ge4+ site, Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with two equivalent GeO6 octahedra and corners with two GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–61°. There are a spread of Ge–O bond distances ranging from 1.76–1.80 Å. In the seventh Ge4+ site, Ge4+ is bonded to six O2- atoms to form corner-sharing GeO6 octahedra. There is three shorter (1.89 Å) and three longer (1.90 Å) Ge–O bond length. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Sr2+ and two Ge4+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Pb2+ and two Ge4+ atoms. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Pb2+ and two Ge4+ atoms. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Sr2+ and two Ge4+ atoms. In the fifth O2- site, O2- is bonded in a bent 120 degrees geometry to one Pb2+ and two Ge4+ atoms. In the sixth O2- site, O2- is bonded in a bent 120 degrees geometry to one Pb2+ and two Ge4+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and two Ge4+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Pb2+ and two Ge4+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Pb2+ and two Ge4+ atoms. In the tenth O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Pb2+ and two Ge4+ atoms. In the eleventh O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent Sr2+ and two equivalent Ge4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Pb2+ and two Ge4+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Sr2+ and two Ge4+ atoms. In the fourteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Pb2+ and two Ge4+ atoms.