DOI: 10.17188/1291063
title: Materials Data on CaGd4O7 by Materials Project

description: CaGd4O7 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to five O2- atoms to form CaO5 trigonal bipyramids that share a cornercorner with one CaO6 octahedra, corners with two GdO6 octahedra, corners with two equivalent GdO5 trigonal bipyramids, and an edgeedge with one GdO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 65–68°. There are a spread of Ca–O bond distances ranging from 2.21–2.51 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent GdO6 octahedra, a cornercorner with one CaO5 trigonal bipyramid, a cornercorner with one GdO5 trigonal bipyramid, an edgeedge with one CaO6 octahedra, and edges with six GdO6 octahedra. The corner-sharing octahedra tilt angles range from 2–3°. There are a spread of Ca–O bond distances ranging from 2.26–2.61 Å. There are eight inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Gd–O bond distances ranging from 2.32–2.55 Å. In the second Gd3+ site, Gd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Gd–O bond distances ranging from 2.31–2.54 Å. In the third Gd3+ site, Gd3+ is bonded to six O2- atoms to form distorted GdO6 octahedra that share corners with two equivalent GdO6 octahedra, a cornercorner with one GdO5 trigonal bipyramid, edges with two equivalent CaO6 octahedra, and edges with three GdO6 octahedra. The corner-sharing octahedra tilt angles range from 3–4°. There are a spread of Gd–O bond distances ranging from 2.23–2.59 Å. In the fourth Gd3+ site, Gd3+ is bonded to six O2- atoms to form GdO6 octahedra that share corners with two equivalent CaO6 octahedra, a cornercorner with one CaO5 trigonal bipyramid, an edgeedge with one CaO6 octahedra, and edges with four GdO6 octahedra. The corner-sharing octahedra tilt angles range from 2–3°. There are a spread of Gd–O bond distances ranging from 2.26–2.51 Å. In the fifth Gd3+ site, Gd3+ is bonded to five O2- atoms to form GdO5 trigonal bipyramids that share a cornercorner with one CaO6 octahedra, corners with two GdO6 octahedra, corners with two equivalent CaO5 trigonal bipyramids, and an edgeedge with one CaO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 64–67°. There are a spread of Gd–O bond distances ranging from 2.16–2.40 Å. In the sixth Gd3+ site, Gd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Gd–O bond distances ranging from 2.27–2.70 Å. In the seventh Gd3+ site, Gd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Gd–O bond distances ranging from 2.26–2.79 Å. In the eighth Gd3+ site, Gd3+ is bonded to six O2- atoms to form GdO6 octahedra that share corners with two equivalent GdO6 octahedra, a cornercorner with one CaO5 trigonal bipyramid, a cornercorner with one GdO5 trigonal bipyramid, edges with three equivalent CaO6 octahedra, and edges with four GdO6 octahedra. The corner-sharing octahedra tilt angles range from 3–4°. There are a spread of Gd–O bond distances ranging from 2.23–2.51 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and three Gd3+ atoms to form OCaGd3 trigonal pyramids that share corners with two equivalent OGd5 square pyramids, corners with six OGd4 tetrahedra, corners with four OCaGd3 trigonal pyramids, and edges with three OCaGd3 trigonal pyramids. In the second O2- site, O2- is bonded to one Ca2+ and three Gd3+ atoms to form OCaGd3 trigonal pyramids that share corners with six OGd4 tetrahedra, corners with four OCaGd3 trigonal pyramids, an edgeedge with one OGd5 square pyramid, and edges with three OCaGd3 trigonal pyramids. In the third O2- site, O2- is bonded to one Ca2+ and three Gd3+ atoms to form distorted OCaGd3 trigonal pyramids that share a cornercorner with one OCa2Gd4 octahedra, corners with seven OCaGd3 tetrahedra, corners with four OCaGd3 trigonal pyramids, an edgeedge with one OGd5 square pyramid, and edges with two OCaGd3 trigonal pyramids. The corner-sharing octahedral tilt angles are 43°. In the fourth O2- site, O2- is bonded to one Ca2+ and three Gd3+ atoms to form distorted OCaGd3 trigonal pyramids that share a cornercorner with one OCaGd5 octahedra, corners with seven OCaGd3 tetrahedra, corners with four OCaGd3 trigonal pyramids, an edgeedge with one OGd5 square pyramid, and edges with two OCaGd3 trigonal pyramids. The corner-sharing octahedral tilt angles are 41°. In the fifth O2- site, O2- is bonded to four Gd3+ atoms to form OGd4 tetrahedra that share corners with two equivalent OCaGd5 octahedra, a cornercorner with one OGd5 square pyramid, corners with four OGd4 tetrahedra, corners with six OCaGd3 trigonal pyramids, an edgeedge with one OCa2Gd4 octahedra, an edgeedge with one OGd5 square pyramid, and an edgeedge with one OGd4 tetrahedra. The corner-sharing octahedra tilt angles range from 11–13°. In the sixth O2- site, O2- is bonded to four Gd3+ atoms to form OGd4 tetrahedra that share corners with two equivalent OCa2Gd4 octahedra, a cornercorner with one OGd5 square pyramid, corners with four OGd4 tetrahedra, corners with six OCaGd3 trigonal pyramids, an edgeedge with one OCaGd5 octahedra, an edgeedge with one OGd5 square pyramid, and an edgeedge with one OGd4 tetrahedra. The corner-sharing octahedra tilt angles range from 13–15°. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to five Gd3+ atoms. In the eighth O2- site, O2- is bonded to five Gd3+ atoms to form distorted OGd5 square pyramids that share corners with seven OCaGd3 tetrahedra, corners with two equivalent OCaGd3 trigonal pyramids, edges with two OCa2Gd4 octahedra, edges with three OGd4 tetrahedra, and edges with three OCaGd3 trigonal pyramids. In the ninth O2- site, O2- is bonded to two Ca2+ and two Gd3+ atoms to form OCa2Gd2 tetrahedra that share corners with two equivalent OCa2Gd4 octahedra, a cornercorner with one OGd5 square pyramid, corners with six OCaGd3 tetrahedra, corners with four OCaGd3 trigonal pyramids, and edges with three OCa2Gd4 octahedra. The corner-sharing octahedral tilt angles are 12°. In the tenth O2- site, O2- is bonded to one Ca2+ and three Gd3+ atoms to form OCaGd3 tetrahedra that share corners with two equivalent OCaGd5 octahedra, corners with six OCaGd3 tetrahedra, corners with four OCaGd3 trigonal pyramids, and edges with three OCa2Gd4 octahedra. The corner-sharing octahedral tilt angles are 12°. In the eleventh O2- site, O2- is bonded to two equivalent Ca2+ and four Gd3+ atoms to form OCa2Gd4 octahedra that share corners with six OCaGd3 tetrahedra, a cornercorner with one OCaGd3 trigonal pyramid, edges with four OCa2Gd4 octahedra, an edgeedge with one OGd5 square pyramid, and edges with six OCaGd3 tetrahedra. In the twelfth O2- site, O2- is bonded to one Ca2+ and five Gd3+ atoms to form OCaGd5 octahedra that share corners with six OGd4 tetrahedra, a cornercorner with one OCaGd3 trigonal pyramid, edges with four OCa2Gd4 octahedra, an edgeedge with one OGd5 square pyramid, and edges with six OCaGd3 tetrahedra. In the thirteenth O2- site, O2- is bonded to one Ca2+ and three Gd3+ atoms to form OCaGd3 tetrahedra that share corners with two equivalent OCa2Gd4 octahedra, corners with three equivalent OGd5 square pyramids, corners with four OGd4 tetrahedra, corners with three OCaGd3 trigonal pyramids, edges with two OCa2Gd4 octahedra, and edges with two OCaGd3 tetrahedra. The corner-sharing octahedra tilt angles range from 10–43°. In the fourteenth O2- site, O2- is bonded to four Gd3+ atoms to form OGd4 tetrahedra that share corners with two equivalent OCaGd5 octahedra, a cornercorner with one OGd5 square pyramid, corners with four OCaGd3 tetrahedra, corners with three OCaGd3 trigonal pyramids, edges with two OCa2Gd4 octahedra, an edgeedge with one OGd5 square pyramid, and edges with two OCaGd3 tetrahedra. The corner-sharing octahedra tilt angles range from 9–43°.