Materials Data on K2Dy4Cu4Se9 by Materials Project

Abstract

K2Dy4Cu4Se9 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a 7-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.28–3.99 Å. There are two inequivalent Dy3+ sites. In the first Dy3+ site, Dy3+ is bonded to six Se2- atoms to form DySe6 octahedra that share a cornercorner with one DySe6 octahedra, corners with four equivalent CuSe4 tetrahedra, edges with four equivalent DySe6 octahedra, and edges with five CuSe4 tetrahedra. The corner-sharing octahedral tilt angles are 39°. There are a spread of Dy–Se bond distances ranging from 2.83–2.93 Å. In the second Dy3+ site, Dy3+ is bonded to six Se2- atoms to form DySe6 octahedra that share corners with three DySe6 octahedra, a cornercorner with one CuSe4 tetrahedra, edges with five equivalent DySe6 octahedra, and edges with two equivalent CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–39°. There are a spread of Dy–Se bond distances ranging from 2.81–2.94 Å. There are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with four equivalent DySe6 octahedra, corners with four CuSe4 tetrahedra, edges with three equivalent DySe6 octahedra, and an edgeedge with one CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 19–63°. There are a spread of Cu–Se bond distances ranging from 2.47–2.60 Å. In the second Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share a cornercorner with one DySe6 octahedra, corners with four CuSe4 tetrahedra, and edges with four DySe6 octahedra. The corner-sharing octahedral tilt angles are 8°. There are a spread of Cu–Se bond distances ranging from 2.46–2.62 Å. There are five inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one K1+, three equivalent Dy3+, and two equivalent Cu1+ atoms to form distorted SeKDy3Cu2 octahedra that share corners with two equivalent SeK2Dy3Cu octahedra and edges with four equivalent SeKDy3Cu2 octahedra. The corner-sharing octahedral tilt angles are 41°. In the second Se2- site, Se2- is bonded in a 7-coordinate geometry to two equivalent K1+, two equivalent Dy3+, and three Cu1+ atoms. In the third Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent K1+, two Dy3+, and two equivalent Cu1+ atoms. In the fourth Se2- site, Se2- is bonded to two equivalent K1+, three equivalent Dy3+, and one Cu1+ atom to form distorted SeK2Dy3Cu octahedra that share corners with two equivalent SeKDy3Cu2 octahedra and edges with four equivalent SeK2Dy3Cu octahedra. The corner-sharing octahedral tilt angles are 41°. In the fifth Se2- site, Se2- is bonded in a square co-planar geometry to two equivalent K1+ and four equivalent Dy3+ atoms.