Materials Data on U2Cu(SiO9)2 by Materials Project

U2Cu(SiO8)2O2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional and consists of two water molecules and one U2Cu(SiO8)2 framework. In the U2Cu(SiO8)2 framework, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one CuO6 octahedra, corners with three equivalent SiO4 tetrahedra, edges with two equivalent UO7 pentagonal bipyramids, and an edgeedge with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 39°. There are a spread of U–O bond distances ranging from 1.83–2.51 Å. Cu is bonded to six O atoms to form distorted CuO6 octahedra that share corners with two equivalent UO7 pentagonal bipyramids. There are a spread of Cu–O bond distances ranging from 1.79–2.51 Å. Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three equivalent UO7 pentagonal bipyramids and an edgeedge with one UO7 pentagonal bipyramid. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one U and one Cu atom. In the second O site, O is bonded in a single-bond geometry to one U atom. In the third O site, O is bonded in a 1-coordinate geometry to two equivalent U and one Si atom. In the fourth O site, O is bonded in a 1-coordinate geometry to two equivalent U and one Si atom. In the fifth O site, O is bonded in a single-bond geometry to one Si atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one U and one Si atom. In the seventh O site, O is bonded in a single-bond geometry to one Cu atom. In the eighth O site, O is bonded in a single-bond geometry to one Cu atom.