Materials Data on Sr5U3O14 by Materials Project

Abstract

Sr5U3O14 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.65–2.97 Å. In the second Sr2+ site, Sr2+ is bonded to seven O2- atoms to form distorted SrO7 pentagonal bipyramids that share corners with three UO6 octahedra, a cornercorner with one SrO7 pentagonal bipyramid, edges with three UO6 octahedra, and edges with three equivalent SrO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 46–62°. There are a spread of Sr–O bond distances ranging from 2.50–2.77 Å. In the third Sr2+ site, Sr2+ is bonded to seven O2- atoms to form distorted SrO7 pentagonal bipyramids that share corners with three UO6 octahedra, a cornercorner with one SrO7 pentagonal bipyramid, edges with three UO6 octahedra, and edges with three equivalent SrO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 37–45°. There are a spread of Sr–O bond distances ranging from 2.46–2.66 Å. There are two inequivalent U6+ sites. In the first U6+ site, U6+ is bonded to six O2- atoms to form UO6 octahedra that share corners with four equivalent UO6 octahedra, corners with four SrO7 pentagonal bipyramids, and edges with four SrO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 41–50°. There are a spread of U–O bond distances ranging from 1.96–2.15 Å. In the second U6+ site, U6+ is bonded to six O2- atoms to form UO6 octahedra that share corners with two equivalent UO6 octahedra, corners with four SrO7 pentagonal bipyramids, and edges with four SrO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 41–50°. There are a spread of U–O bond distances ranging from 2.04–2.23 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Sr2+ and one U6+ atom. In the second O2- site, O2- is bonded to three Sr2+ and one U6+ atom to form distorted OSr3U tetrahedra that share a cornercorner with one OSr3U tetrahedra and corners with three equivalent OSr2U2 trigonal pyramids. In the third O2- site, O2- is bonded to two Sr2+ and two U6+ atoms to form distorted OSr2U2 trigonal pyramids that share corners with three equivalent OSr3U tetrahedra and a cornercorner with one OSr2U2 trigonal pyramid. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one U6+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+ and two U6+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one U6+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one U6+ atom.