DOI: 10.17188/1729570
title: Materials Data on K2U2Cr2H2O17 by Materials Project

description: K2U2Cr2H2O17 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of K–O bond distances ranging from 2.68–3.35 Å. In the second K site, K is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of K–O bond distances ranging from 2.86–3.33 Å. There are two 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 three CrO4 tetrahedra and an edgeedge with one UO7 pentagonal bipyramid. There are a spread of U–O bond distances ranging from 1.82–2.41 Å. In the second U site, U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share corners with three CrO4 tetrahedra and an edgeedge with one UO7 pentagonal bipyramid. There are a spread of U–O bond distances ranging from 1.83–2.39 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded to four O atoms to form CrO4 tetrahedra that share corners with three UO7 pentagonal bipyramids. There are a spread of Cr–O bond distances ranging from 1.61–1.70 Å. In the second Cr site, Cr is bonded to four O atoms to form CrO4 tetrahedra that share corners with three UO7 pentagonal bipyramids. There are a spread of Cr–O bond distances ranging from 1.62–1.69 Å. There are two inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.98 Å. In the second H site, H is bonded in a single-bond geometry to one O atom. The H–O bond length is 0.97 Å. There are seventeen inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to two equivalent K and one U atom. In the second O site, O is bonded in a single-bond geometry to one K and one U atom. 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 distorted single-bond geometry to two equivalent K and one U atom. In the fifth O site, O is bonded in a 1-coordinate geometry to one K, one U, and one Cr atom. In the sixth O site, O is bonded in a distorted bent 150 degrees geometry to one U and one Cr atom. In the seventh O site, O is bonded in a distorted linear geometry to one U and one Cr atom. In the eighth O site, O is bonded in a distorted single-bond geometry to two equivalent K and one Cr atom. In the ninth O site, O is bonded in a distorted bent 150 degrees geometry to one U and one Cr atom. In the tenth O site, O is bonded in a 1-coordinate geometry to one K, one U, and one Cr atom. In the eleventh O site, O is bonded in a distorted linear geometry to one U and one Cr atom. In the twelfth O site, O is bonded in a distorted single-bond geometry to one K and one Cr atom. In the thirteenth O site, O is bonded in a distorted bent 120 degrees geometry to one K and two U atoms. In the fourteenth O site, O is bonded in a distorted bent 120 degrees geometry to one K and two U atoms. In the fifteenth O site, O is bonded in a single-bond geometry to one K atom. In the sixteenth O site, O is bonded in a distorted single-bond geometry to one K and one O atom. The O–O bond length is 1.23 Å. In the seventeenth O site, O is bonded in a distorted water-like geometry to one K and two H atoms.