Materials Data on Sr3U(Te2O7)2 by Materials Project
Sr3U(Te2O7)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to seven O2- atoms to form distorted SrO7 pentagonal bipyramids that share a cornercorner with one UO6 octahedra and edges with two equivalent SrO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 70°. There are a spread of Sr–O bond distances ranging from 2.49–2.73 Å. In the second Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.59–2.80 Å. U6+ is bonded to six O2- atoms to form UO6 octahedra that share corners with two equivalent SrO7 pentagonal bipyramids. There are a spread of U–O bond distances ranging from 1.86–2.28 Å. There are two inequivalent Te4+ sites. In the first Te4+ site, Te4+ is bonded in a 3-coordinate geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.87–2.85 Å. In the second Te4+ site, Te4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.89 Å) and two longer (1.90 Å) Te–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Sr2+ and one Te4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Sr2+ and two Te4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Sr2+, one U6+, and one Te4+ atom. In the fourth O2- site, O2- is bonded to three Sr2+ and one Te4+ atom to form a mixture of distorted corner and edge-sharing OSr3Te tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one Te4+ atom. In the sixth O2- site, O2- is bonded in a linear geometry to one U6+ and one Te4+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one U6+ atom.