Materials Data on KUSiO7 by Materials Project
KUSiO7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. K is bonded in a 7-coordinate geometry to eight O atoms. There are a spread of K–O bond distances ranging from 2.78–3.37 Å. U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share corners with three equivalent SiO4 tetrahedra, edges with two equivalent UO7 pentagonal bipyramids, and an edgeedge with one SiO4 tetrahedra. There are a spread of U–O bond distances ranging from 1.83–2.51 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 1.63–1.67 Å. There are seven inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one K and one U atom. In the second O site, O is bonded in a distorted single-bond geometry to two equivalent K and 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 2-coordinate geometry to one K, one U, and one Si atom. In the sixth O site, O is bonded in a distorted single-bond geometry to two equivalent K, one Si, and one O atom. The O–O bond length is 1.95 Å. In the seventh O site, O is bonded in a 2-coordinate geometry to two equivalent K and one O atom.