DOE OSTI2020
Re8Pb8O27 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are sixteen inequivalent Re+4.75+ sites. In the first Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six equivalent PbO7 hexagonal pyramids. The corner-sharing octahedral tilt angles are 41°. There is three shorter (1.99 Å) and three longer (2.00 Å) Re–O bond length. In the second Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 40–41°. There is two shorter (1.99 Å) and four longer (2.00 Å) Re–O bond length. In the third Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six equivalent PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 41–42°. All Re–O bond lengths are 2.00 Å. In the fourth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 40–42°. There are a spread of Re–O bond distances ranging from 1.99–2.01 Å. In the fifth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 41–42°. There is three shorter (1.99 Å) and three longer (2.00 Å) Re–O bond length. In the sixth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six equivalent PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 40–41°. There is three shorter (1.99 Å) and three longer (2.00 Å) Re–O bond length. In the seventh Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six equivalent PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 41–43°. There are three shorter (2.00 Å) and three longer (2.01 Å) Re–O bond lengths. In the eighth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra, edges with two equivalent PbO8 hexagonal bipyramids, and edges with four PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 37–43°. There are a spread of Re–O bond distances ranging from 1.95–2.03 Å. In the ninth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six PbO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–40°. There are a spread of Re–O bond distances ranging from 1.97–1.99 Å. In the tenth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six equivalent PbO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 37–39°. There is three shorter (1.99 Å) and three longer (2.00 Å) Re–O bond length. In the eleventh Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six equivalent PbO8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There is three shorter (1.98 Å) and three longer (1.99 Å) Re–O bond length. In the twelfth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six PbO8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There is four shorter (1.98 Å) and two longer (1.99 Å) Re–O bond length. In the thirteenth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six PbO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–40°. There is one shorter (1.97 Å) and five longer (1.99 Å) Re–O bond length. In the fourteenth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six equivalent PbO8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There is three shorter (1.98 Å) and three longer (1.99 Å) Re–O bond length. In the fifteenth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra and edges with six equivalent PbO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 37–39°. There is three shorter (1.98 Å) and three longer (2.00 Å) Re–O bond length. In the sixteenth Re+4.75+ site, Re+4.75+ is bonded to six O2- atoms to form ReO6 octahedra that share corners with six ReO6 octahedra, edges with four PbO8 hexagonal bipyramids, and edges with two equivalent PbO7 hexagonal pyramids. The corner-sharing octahedra tilt angles range from 37–43°. There are a spread of Re–O bond distances ranging from 1.95–2.02 Å. There are sixteen inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to seven O2- atoms to form distorted PbO7 hexagonal pyramids that share corners with three PbO7 hexagonal pyramids, an edgeedge with one PbO8 hexagonal bipyramid, edges with two equivalent PbO7 hexagonal pyramids, and edges with six ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.23–2.72 Å. In the second Pb2+ site, Pb2+ is bonded to seven O2- atoms to form distorted PbO7 hexagonal pyramids that share corners with three PbO7 hexagonal pyramids, edges with three PbO7 hexagonal pyramids, and edges with six ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.33–2.71 Å. In the third Pb2+ site, Pb2+ is bonded to seven O2- atoms to form distorted PbO7 hexagonal pyramids that share corners with three equivalent PbO7 hexagonal pyramids, edges with three equivalent PbO7 hexagonal pyramids, and edges with six equivalent ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.31–2.70 Å. In the fourth Pb2+ site, Pb2+ is bonded to seven O2- atoms to form distorted PbO7 hexagonal pyramids that share corners with three PbO7 hexagonal pyramids, edges with three PbO7 hexagonal pyramids, and edges with six ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.33–2.71 Å. In the fifth Pb2+ site, Pb2+ is bonded to seven O2- atoms to form distorted PbO7 hexagonal pyramids that share corners with three equivalent PbO7 hexagonal pyramids, edges with three equivalent PbO7 hexagonal pyramids, and edges with six equivalent ReO6 octahedra. There are one shorter (2.33 Å) and six longer (2.70 Å) Pb–O bond lengths. In the sixth Pb2+ site, Pb2+ is bonded to seven O2- atoms to form distorted PbO7 hexagonal pyramids that share corners with three equivalent PbO7 hexagonal pyramids, edges with three equivalent PbO8 hexagonal bipyramids, and edges with six equivalent ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.08–2.75 Å. In the seventh Pb2+ site, Pb2+ is bonded to seven O2- atoms to form distorted PbO7 hexagonal pyramids that share corners with three PbO7 hexagonal pyramids, edges with three PbO7 hexagonal pyramids, and edges with six ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.32–2.72 Å. In the eighth Pb2+ site, Pb2+ is bonded to eight O2- atoms to form distorted PbO8 hexagonal bipyramids that share edges with five PbO8 hexagonal bipyramids, an edgeedge with one PbO7 hexagonal pyramid, and edges with six ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.27–2.79 Å. In the ninth Pb2+ site, Pb2+ is bonded to seven O2- atoms to form distorted PbO7 hexagonal pyramids that share corners with three equivalent PbO7 hexagonal pyramids, edges with three equivalent PbO7 hexagonal pyramids, and edges with six equivalent ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.33–2.70 Å. In the tenth Pb2+ site, Pb2+ is bonded to eight O2- atoms to form distorted PbO8 hexagonal bipyramids that share edges with six PbO8 hexagonal bipyramids and edges with six equivalent ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.25–2.73 Å. In the eleventh Pb2+ site, Pb2+ is bonded to eight O2- atoms to form distorted PbO8 hexagonal bipyramids that share edges with six PbO8 hexagonal bipyramids and edges with six ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.29–2.73 Å. In the twelfth Pb2+ site, Pb2+ is bonded to eight O2- atoms to form distorted PbO8 hexagonal bipyramids that share edges with six PbO8 hexagonal bipyramids and edges with six equivalent ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.28–2.72 Å. In the thirteenth Pb2+ site, Pb2+ is bonded to eight O2- atoms to form distorted PbO8 hexagonal bipyramids that share edges with six PbO8 hexagonal bipyramids and edges with six ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.29–2.73 Å. In the fourteenth Pb2+ site, Pb2+ is bonded to eight O2- atoms to form distorted PbO8 hexagonal bipyramids that share edges with six PbO8 hexagonal bipyramids and edges with six ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.28–2.77 Å. In the fifteenth Pb2+ site, Pb2+ is bonded to eight O2- atoms to form distorted PbO8 hexagonal bipyramids that share edges with six PbO8 hexagonal bipyramids and edges with six equivalent ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.29–2.73 Å. In the sixteenth Pb2+ site, Pb2+ is bonded to eight O2- atoms to form distorted PbO8 hexagonal bipyramids that share edges with three equivalent PbO8 hexagonal bipyramids, edges with three equivalent PbO7 hexagonal pyramids, and edges with six equivalent ReO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.18–2.73 Å. There are forty-four inequivalent O2- sites. In the first O2- site, O2- is bonded to four Pb2+ atoms to form distorted corner-sharing OPb4 tetrahedra. In the second O2- site, O2- is bonded to four Pb2+ atoms to form corner-sharing OPb4 tetrahedra. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Re+4.75+ and two equivalent Pb2+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Re+4.75+ and two Pb2+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Re+4.75+ and two Pb2+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Re+4.75+ and two equivalent Pb2+ atoms. In the seventh O2- site, O2- is bonded to four Pb2+ atoms to form corner-sharing OPb4 tetrahedra. In the eighth O2- site, O2- is bonded to four Pb2+ atoms to form corner-sharing OPb4 tetrahedra. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Re+4.75+ and two Pb2+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Re+4.75+ and two Pb2+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Re+4.75+ and two equivalent Pb2+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Re+4.75+ and two equivalent Pb2+ atoms. In the thirteenth O2- site, O2- is bonded to four Pb2+ atoms to form corner-sharing OPb4 tetrahedra. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Re+4.75+ and two equivalent Pb2+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Re+4.75+ and two Pb2+ atoms. In the sixteenth O2- site, O2- is bonded to four Pb2+ atoms to form corner-sharing OPb4 tetrahedra. In the seventeenth O2- site, O2- is bonded