DOI: 10.17188/1732522
title: Materials Data on K6U5As2O23 by Materials Project

description: K6U5As2O23 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six O2- atoms to form distorted KO6 octahedra that share a cornercorner with one UO6 octahedra, corners with four UO7 pentagonal bipyramids, and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are a spread of K–O bond distances ranging from 2.61–2.84 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.73–2.94 Å. In the third K1+ site, K1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of K–O bond distances ranging from 2.77–2.94 Å. There are three 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 two equivalent KO6 octahedra, corners with two equivalent UO6 octahedra, a cornercorner with one UO7 pentagonal bipyramid, edges with two equivalent UO7 pentagonal bipyramids, and an edgeedge with one AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–62°. There are a spread of U–O bond distances ranging from 1.88–2.52 Å. In the second U6+ site, U6+ is bonded to seven O2- atoms to form distorted UO7 pentagonal bipyramids that share corners with two equivalent KO6 octahedra, corners with three equivalent AsO4 tetrahedra, an edgeedge with one UO6 octahedra, and edges with two equivalent UO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 55–56°. There are a spread of U–O bond distances ranging from 1.85–2.42 Å. In the third U6+ site, U6+ is bonded to six O2- atoms to form UO6 octahedra that share corners with two equivalent KO6 octahedra, corners with four equivalent UO7 pentagonal bipyramids, and edges with two equivalent UO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 61°. There are a spread of U–O bond distances ranging from 1.88–2.28 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share a cornercorner with one KO6 octahedra, corners with three equivalent UO7 pentagonal bipyramids, and an edgeedge with one UO7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 79°. There are a spread of As–O bond distances ranging from 1.68–1.75 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one U6+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two U6+ and one As5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three K1+ and one U6+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two U6+ and one As5+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one U6+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three K1+ and one U6+ atom. In the seventh O2- site, O2- is bonded in a linear geometry to two equivalent U6+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to three U6+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to three U6+ atoms. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to three K1+ and one As5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to two K1+ and one U6+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one U6+ and one As5+ atom.