DOI: 10.17188/1317212
title: Materials Data on Ce4GdO9 by Materials Project

description: GdCe4O9 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Gd3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Gd–O bond distances ranging from 2.26–2.36 Å. There are four inequivalent Ce+3.75+ sites. In the first Ce+3.75+ site, Ce+3.75+ is bonded to seven O2- atoms to form a mixture of distorted edge and corner-sharing CeO7 hexagonal pyramids. There are a spread of Ce–O bond distances ranging from 2.27–2.42 Å. In the second Ce+3.75+ site, Ce+3.75+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ce–O bond distances ranging from 2.33–2.62 Å. In the third Ce+3.75+ site, Ce+3.75+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ce–O bond distances ranging from 2.32–2.68 Å. In the fourth Ce+3.75+ site, Ce+3.75+ is bonded to seven O2- atoms to form a mixture of distorted edge and corner-sharing CeO7 hexagonal pyramids. There are a spread of Ce–O bond distances ranging from 2.25–2.43 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ce+3.75+ atoms to form OCe4 tetrahedra that share corners with fourteen OCe4 tetrahedra, a cornercorner with one OCe3Gd trigonal pyramid, edges with four OCe4 tetrahedra, and edges with two equivalent OCe3Gd trigonal pyramids. In the second O2- site, O2- is bonded to one Gd3+ and three Ce+3.75+ atoms to form distorted OCe3Gd trigonal pyramids that share corners with thirteen OCe3Gd tetrahedra, corners with three OCe3Gd trigonal pyramids, and edges with four OCe4 tetrahedra. In the third O2- site, O2- is bonded to one Gd3+ and three Ce+3.75+ atoms to form OCe3Gd tetrahedra that share corners with nine OCe4 tetrahedra, corners with three OCe3Gd trigonal pyramids, edges with four OCe4 tetrahedra, and edges with two equivalent OCe3Gd trigonal pyramids. In the fourth O2- site, O2- is bonded to four Ce+3.75+ atoms to form OCe4 tetrahedra that share corners with ten OCe4 tetrahedra, corners with five OCe3Gd trigonal pyramids, and edges with six OCe4 tetrahedra. In the fifth O2- site, O2- is bonded to four Ce+3.75+ atoms to form OCe4 tetrahedra that share corners with fourteen OCe4 tetrahedra, a cornercorner with one OCe3Gd trigonal pyramid, edges with four OCe4 tetrahedra, and edges with two equivalent OCe3Gd trigonal pyramids. In the sixth O2- site, O2- is bonded to one Gd3+ and three Ce+3.75+ atoms to form distorted OCe3Gd trigonal pyramids that share corners with thirteen OCe4 tetrahedra, corners with three OCe3Gd trigonal pyramids, and edges with four OCe4 tetrahedra. In the seventh O2- site, O2- is bonded to one Gd3+ and three Ce+3.75+ atoms to form OCe3Gd tetrahedra that share corners with nine OCe4 tetrahedra, corners with three OCe3Gd trigonal pyramids, edges with four OCe2Gd2 tetrahedra, and edges with two equivalent OCe3Gd trigonal pyramids. In the eighth O2- site, O2- is bonded to two equivalent Gd3+ and two Ce+3.75+ atoms to form OCe2Gd2 tetrahedra that share corners with six OCe4 tetrahedra, corners with eight OCe3Gd trigonal pyramids, and edges with four OCe3Gd tetrahedra. In the ninth O2- site, O2- is bonded to four Ce+3.75+ atoms to form OCe4 tetrahedra that share corners with ten OCe3Gd tetrahedra, corners with five OCe3Gd trigonal pyramids, and edges with six OCe4 tetrahedra.