Materials Data on Er7CoI12 by Materials Project
Er7CoI12 is trigonal omega-derived structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Er sites. In the first Er site, Er is bonded to six equivalent I atoms to form edge-sharing ErI6 octahedra. All Er–I bond lengths are 3.01 Å. In the second Er site, Er is bonded to one Co and five I atoms to form distorted ErCoI5 octahedra that share corners with three equivalent ErCoI5 octahedra and edges with six ErI6 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. The Er–Co bond length is 2.56 Å. There are a spread of Er–I bond distances ranging from 3.07–3.46 Å. Co is bonded in an octahedral geometry to six equivalent Er atoms. There are two inequivalent I sites. In the first I site, I is bonded in a distorted T-shaped geometry to three Er atoms. In the second I site, I is bonded in a 3-coordinate geometry to three equivalent Er atoms.