DOE OSTI2020
Y6C2I7 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one Y6C2I7 sheet oriented in the (0, 0, 1) direction. there are three inequivalent Y sites. In the first Y site, Y is bonded in a 5-coordinate geometry to one C and four I atoms. The Y–C bond length is 2.37 Å. There are two shorter (3.03 Å) and two longer (3.07 Å) Y–I bond lengths. In the second Y site, Y is bonded to three equivalent C and three I atoms to form distorted edge-sharing YC3I3 octahedra. There are one shorter (2.57 Å) and two longer (2.65 Å) Y–C bond lengths. There are two shorter (3.17 Å) and one longer (3.31 Å) Y–I bond lengths. In the third Y site, Y is bonded in a 6-coordinate geometry to two equivalent C and four I atoms. Both Y–C bond lengths are 2.53 Å. There are a spread of Y–I bond distances ranging from 3.00–3.33 Å. C is bonded to six Y atoms to form edge-sharing CY6 octahedra. There are four inequivalent I sites. In the first I site, I is bonded in a 3-coordinate geometry to three Y atoms. In the second I site, I is bonded in a 3-coordinate geometry to three Y atoms. In the third I site, I is bonded in a distorted rectangular see-saw-like geometry to four equivalent Y atoms. In the fourth I site, I is bonded in a 3-coordinate geometry to three Y atoms.