Materials Data on KU11(GeO19)2 by Materials Project

Abstract

KU11(GeO19)2 crystallizes in the trigonal P-31c space group. The structure is three-dimensional. K is bonded in a 6-coordinate geometry to six equivalent O atoms. All K–O bond lengths are 2.85 Å. There are three inequivalent U sites. In the first U site, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share corners with two equivalent UO6 octahedra, corners with two equivalent UO7 pentagonal bipyramids, corners with two equivalent GeO4 tetrahedra, and edges with two equivalent UO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 32°. There are a spread of U–O bond distances ranging from 1.80–2.54 Å. In the second U site, U is bonded to six O atoms to form a mixture of edge and corner-sharing UO6 octahedra. There are three shorter (2.07 Å) and three longer (2.13 Å) U–O bond lengths. In the third U site, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one UO6 octahedra, corners with two equivalent UO7 pentagonal bipyramids, a cornercorner with one GeO4 tetrahedra, an edgeedge with one UO6 octahedra, and edges with two UO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 35°. There are a spread of U–O bond distances ranging from 1.81–2.49 Å. Ge is bonded to four O atoms to form GeO4 tetrahedra that share corners with six UO7 pentagonal bipyramids and a cornercorner with one GeO4 tetrahedra. There is one shorter (1.73 Å) and three longer (1.77 Å) Ge–O bond length. There are eight inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two equivalent U atoms. In the second O site, O is bonded in a trigonal planar geometry to three equivalent U atoms. In the third O site, O is bonded in a distorted single-bond geometry to one K and 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 distorted trigonal planar geometry to two U and one Ge atom. In the sixth O site, O is bonded in a distorted trigonal non-coplanar geometry to three U atoms. In the seventh O site, O is bonded in a linear geometry to two equivalent Ge atoms. In the eighth O site, O is bonded in a 3-coordinate geometry to three U atoms.