Materials Data on UI2O9 by Materials Project
UO9I2 crystallizes in the orthorhombic Pbcn space group. The structure is two-dimensional and consists of two UO9I2 sheets oriented in the (0, 0, 1) direction. U is bonded in a distorted pentagonal bipyramidal geometry to seven O atoms. There are a spread of U–O bond distances ranging from 1.83–2.42 Å. There are five inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one I atom. The O–I bond length is 1.84 Å. In the second O site, O is bonded in a bent 150 degrees geometry to one U and one I atom. The O–I bond length is 1.83 Å. In the third O site, O is bonded in a single-bond geometry to one U atom. In the fourth O site, O is bonded in a single-bond geometry to one U atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to one U and one I atom. The O–I bond length is 1.86 Å. I is bonded in a 3-coordinate geometry to three O atoms.