Materials Data on K4U3(AsO8)2 by Materials Project
K4U3(AsO8)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.65–3.22 Å. In the second K1+ site, K1+ is bonded in a 3-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.71–3.44 Å. There are two inequivalent U6+ sites. In the first U6+ site, U6+ is bonded to seven O2- atoms to form distorted UO7 pentagonal bipyramids that share corners with three equivalent AsO4 tetrahedra and an edgeedge with one UO7 pentagonal bipyramid. There are a spread of U–O bond distances ranging from 1.86–2.41 Å. In the second U6+ site, U6+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 1.85–2.64 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with three equivalent UO7 pentagonal bipyramids. There are a spread of As–O bond distances ranging from 1.69–1.75 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one U6+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three K1+ and one U6+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one K1+ and three U6+ atoms. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one U6+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three K1+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one U6+, and one As5+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, two U6+, and one As5+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, two U6+, and one As5+ atom.