Materials Data on YCuF5 by Materials Project
YCuF5 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Y3+ is bonded to six F1- atoms to form YF6 octahedra that share corners with two equivalent YF6 octahedra and corners with six equivalent CuF6 octahedra. The corner-sharing octahedra tilt angles range from 0–58°. There are a spread of Y–F bond distances ranging from 2.12–2.21 Å. Cu2+ is bonded to six F1- atoms to form distorted CuF6 octahedra that share corners with six equivalent YF6 octahedra and edges with two equivalent CuF6 octahedra. The corner-sharing octahedra tilt angles range from 0–58°. There are two shorter (1.82 Å) and four longer (2.48 Å) Cu–F bond lengths. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal planar geometry to one Y3+ and two equivalent Cu2+ atoms. Both F–Cu bond lengths are 2.48 Å. In the second F1- site, F1- is bonded in a distorted trigonal planar geometry to one Y3+ and two equivalent Cu2+ atoms. Both F–Cu bond lengths are 2.48 Å. In the third F1- site, F1- is bonded in a linear geometry to one Y3+ and one Cu2+ atom. In the fourth F1- site, F1- is bonded in a linear geometry to two equivalent Y3+ atoms. In the fifth F1- site, F1- is bonded in a distorted trigonal planar geometry to one Y3+ and two equivalent Cu2+ atoms. The F–Y bond length is 2.18 Å.