Materials Data on YIO9 by Materials Project
YO9I crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one YO9I sheet oriented in the (1, 0, 0) direction. Y is bonded to seven O atoms to form distorted YO7 pentagonal bipyramids that share a cornercorner with one IO5 trigonal bipyramid, an edgeedge with one YO7 pentagonal bipyramid, and edges with two equivalent IO5 trigonal bipyramids. There are a spread of Y–O bond distances ranging from 2.27–2.52 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two O atoms. There is one shorter (1.27 Å) and one longer (1.33 Å) O–O bond length. In the second O site, O is bonded in a water-like geometry to one Y and one O atom. In the third O site, O is bonded in a water-like geometry to one Y and one I atom. The O–I bond length is 1.86 Å. In the fourth O site, O is bonded in a distorted single-bond geometry to one Y atom. In the fifth O site, O is bonded in a single-bond geometry to one I atom. The O–I bond length is 1.86 Å. In the sixth O site, O is bonded in a water-like geometry to one Y and one I atom. The O–I bond length is 1.85 Å. In the seventh O site, O is bonded in a single-bond geometry to one O atom. In the eighth O site, O is bonded in a water-like geometry to one Y and one I atom. The O–I bond length is 1.85 Å. In the ninth O site, O is bonded in a distorted trigonal non-coplanar geometry to two equivalent Y and one I atom. The O–I bond length is 1.94 Å. I is bonded to five O atoms to form IO5 trigonal bipyramids that share a cornercorner with one YO7 pentagonal bipyramid and edges with two equivalent YO7 pentagonal bipyramids.