DOI: 10.17188/1759312
title: Materials Data on Ba4U8As2O33 by Materials Project

description: Ba4U8As2O33 crystallizes in the orthorhombic Pmn2_1 space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.60–3.29 Å. In the second Ba2+ site, Ba2+ is bonded to eight O2- atoms to form distorted BaO8 hexagonal bipyramids that share corners with four UO6 octahedra, corners with two equivalent UO7 pentagonal bipyramids, and edges with two equivalent AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–52°. There are a spread of Ba–O bond distances ranging from 2.72–2.92 Å. In the third Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.76–3.18 Å. There are five inequivalent U6+ sites. In the first U6+ site, U6+ is bonded to seven O2- atoms to form UO7 pentagonal bipyramids that share a cornercorner with one BaO8 hexagonal bipyramid, corners with two equivalent UO6 octahedra, a cornercorner with one UO7 pentagonal bipyramid, an edgeedge with one UO6 octahedra, and edges with two equivalent UO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 37–39°. There are a spread of U–O bond distances ranging from 1.87–2.38 Å. In the second U6+ site, U6+ is bonded to six O2- atoms to form UO6 octahedra that share a cornercorner with one BaO8 hexagonal bipyramid, corners with four equivalent UO7 pentagonal bipyramids, corners with two AsO4 tetrahedra, and edges with two equivalent UO7 pentagonal bipyramids. There are a spread of U–O bond distances ranging from 2.02–2.26 Å. In the third U6+ site, U6+ is bonded to six O2- atoms to form distorted UO6 octahedra that share a cornercorner with one BaO8 hexagonal bipyramid, corners with two equivalent UO6 octahedra, corners with two equivalent UO7 pentagonal bipyramids, an edgeedge with one UO6 octahedra, and an edgeedge with one UO7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 56°. There are a spread of U–O bond distances ranging from 1.85–2.43 Å. In the fourth U6+ site, U6+ is bonded to six O2- atoms to form UO6 octahedra that share a cornercorner with one BaO8 hexagonal bipyramid, corners with four equivalent UO6 octahedra, corners with two equivalent UO7 pentagonal bipyramids, and corners with two AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 56°. There are a spread of U–O bond distances ranging from 1.91–2.28 Å. In the fifth U6+ site, U6+ is bonded to seven O2- atoms to form distorted UO7 pentagonal bipyramids that share corners with three UO6 octahedra, an edgeedge with one UO6 octahedra, and edges with two equivalent UO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 0–45°. There are a spread of U–O bond distances ranging from 1.83–2.44 Å. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two UO6 octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of As–O bond distances ranging from 1.69–1.76 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two UO6 octahedra and edges with two equivalent BaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of As–O bond distances ranging from 1.69–1.76 Å. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one U6+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one U6+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to three U6+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three U6+ atoms. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two Ba2+ and one As5+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to two Ba2+ and one As5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one U6+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one U6+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one U6+, and one As5+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one U6+, and one As5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one U6+, and one As5+ atom. In the twelfth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+, one U6+, and one As5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three U6+ atoms. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ba2+ and three U6+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Ba2+ and one U6+ atom. In the sixteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Ba2+ and one U6+ atom. In the seventeenth O2- site, O2- is bonded in a trigonal planar geometry to three U6+ atoms. In the eighteenth O2- site, O2- is bonded in a trigonal planar geometry to three U6+ atoms. In the nineteenth O2- site, O2- is bonded in a linear geometry to two U6+ atoms. In the twentieth O2- site, O2- is bonded in a distorted linear geometry to one Ba2+ and two equivalent U6+ atoms.