Results for “Cu-Gd-Se” | Engineering Papers

DOE OSTI2020

Materials Data on GdCuSe2 by Materials Project

GdCuSe2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Gd3+ is bonded to seven Se2- atoms to form distorted GdSe7 pentagonal bipyramids that share corners with four equivalent GdSe7 pentagonal bipyramids, corners with five equivalent CuSe4 tetrahedra, edges with seven equivalent GdSe7 pentagonal bipyramids, and edges with four equivalent CuSe4 tetrahedra. There are a spread of Gd–Se bond distances ranging from 2.91–3.17 Å. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with five equivalent GdSe7 pentagonal bipyramids, corners with four equivalent CuSe4 tetrahedra, edges with four equivalent GdSe7 pentagonal bipyramids, and an edgeedge with one CuSe4 tetrahedra. There are a spread of Cu–Se bond distances ranging from 2.44–2.59 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to three equivalent Gd3+ and three equivalent Cu1+ atoms. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to four equivalent Gd3+ and one Cu1+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on GdCu5Se4 by Materials Project

GdCu5Se4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Gd3+ is bonded to six Se2- atoms to form GdSe6 octahedra that share corners with twelve CuSe4 tetrahedra, edges with two equivalent GdSe6 octahedra, edges with four equivalent CuSe6 octahedra, and edges with six CuSe4 tetrahedra. There are four shorter (2.87 Å) and two longer (2.88 Å) Gd–Se bond lengths. There are three inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to six Se2- atoms to form CuSe6 octahedra that share corners with twelve CuSe4 tetrahedra, edges with two equivalent CuSe6 octahedra, edges with four equivalent GdSe6 octahedra, and edges with six CuSe4 tetrahedra. There are four shorter (2.77 Å) and two longer (2.82 Å) Cu–Se bond lengths. In the second Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share a cornercorner with one GdSe6 octahedra, corners with five equivalent CuSe6 octahedra, corners with six CuSe4 tetrahedra, an edgeedge with one CuSe6 octahedra, edges with two equivalent GdSe6 octahedra, and edges with three CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 13–57°. All Cu–Se bond lengths are 2.54 Å. In the third Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share a cornercorner with one CuSe6 octahedra, corners with five equivalent GdSe6 octahedra, corners with six CuSe4 tetrahedra, an edgeedge with one GdSe6 octahedra, edges with two equivalent CuSe6 octahedra, and edges with three CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 11–56°. There are a spread of Cu–Se bond distances ranging from 2.44–2.48 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Gd3+ and five Cu1+ atoms to form a mixture of distorted corner and edge-sharing SeGd2Cu5 pentagonal bipyramids. In the second Se2- site, Se2- is bonded to one Gd3+ and six Cu1+ atoms to form distorted SeGdCu6 pentagonal bipyramids that share corners with three equivalent SeGdCu6 pentagonal bipyramids and edges with twelve SeGd2Cu5 pentagonal bipyramids.

36 MATERIALS SCIENCE↗