Materials Data on SrGdCuSe3 by Materials Project

Abstract

SrCuGdSe3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sr2+ is bonded to seven Se2- atoms to form distorted SrSe7 pentagonal bipyramids that share corners with six equivalent GdSe6 octahedra, corners with three equivalent CuSe4 tetrahedra, edges with four equivalent GdSe6 octahedra, edges with two equivalent SrSe7 pentagonal bipyramids, edges with three equivalent CuSe4 tetrahedra, and faces with two equivalent SrSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 23–70°. There are a spread of Sr–Se bond distances ranging from 3.14–3.44 Å. Gd3+ is bonded to six Se2- atoms to form GdSe6 octahedra that share corners with two equivalent GdSe6 octahedra, corners with six equivalent SrSe7 pentagonal bipyramids, edges with two equivalent GdSe6 octahedra, edges with four equivalent SrSe7 pentagonal bipyramids, and edges with four equivalent CuSe4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. There are a spread of Gd–Se bond distances ranging from 2.90–2.92 Å. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with three equivalent SrSe7 pentagonal bipyramids, corners with two equivalent CuSe4 tetrahedra, edges with four equivalent GdSe6 octahedra, and edges with three equivalent SrSe7 pentagonal bipyramids. There are a spread of Cu–Se bond distances ranging from 2.47–2.53 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Sr2+, two equivalent Gd3+, and two equivalent Cu1+ atoms to form distorted SeSr2Gd2Cu2 octahedra that share corners with two equivalent SeSr2Gd2Cu2 octahedra, corners with four equivalent SeSr2Gd2Cu square pyramids, edges with two equivalent SeSr2Gd2Cu2 octahedra, and edges with three equivalent SeSr2Gd2Cu square pyramids. The corner-sharing octahedral tilt angles are 3°. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to three equivalent Sr2+, two equivalent Gd3+, and one Cu1+ atom. In the third Se2- site, Se2- is bonded to two equivalent Sr2+, two equivalent Gd3+, and one Cu1+ atom to form distorted SeSr2Gd2Cu square pyramids that share corners with four equivalent SeSr2Gd2Cu2 octahedra, edges with three equivalent SeSr2Gd2Cu2 octahedra, and edges with two equivalent SeSr2Gd2Cu square pyramids. The corner-sharing octahedra tilt angles range from 46–88°.