Materials Data on Sm4U4O17 by Materials Project

Abstract

U4Sm4O17 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent U+5.50+ sites. In the first U+5.50+ site, U+5.50+ is bonded in a body-centered cubic geometry to nine O2- atoms. There are a spread of U–O bond distances ranging from 2.19–2.74 Å. In the second U+5.50+ site, U+5.50+ is bonded in a 8-coordinate geometry to ten O2- atoms. There are a spread of U–O bond distances ranging from 2.18–2.64 Å. There are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Sm–O bond distances ranging from 2.34–2.42 Å. In the second Sm3+ site, Sm3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are six shorter (2.41 Å) and two longer (2.46 Å) Sm–O bond lengths. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to one U+5.50+ and three Sm3+ atoms to form a mixture of edge and corner-sharing OSm3U tetrahedra. In the second O2- site, O2- is bonded to three U+5.50+, one Sm3+, and one O2- atom to form distorted OSmU3O tetrahedra that share corners with fourteen OSm3U tetrahedra, edges with six OSm3U tetrahedra, and faces with three OSmU3O tetrahedra. The O–O bond length is 2.34 Å. In the third O2- site, O2- is bonded to one U+5.50+ and three Sm3+ atoms to form a mixture of distorted edge and corner-sharing OSm3U tetrahedra. In the fourth O2- site, O2- is bonded to four U+5.50+ and two equivalent O2- atoms to form OU4O2 tetrahedra that share corners with twelve OSm3U tetrahedra, edges with seven OSmU3O tetrahedra, and faces with five OSmU3O tetrahedra. Both O–O bond lengths are 2.46 Å. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to six U+5.50+ and eight O2- atoms. In the sixth O2- site, O2- is bonded to two equivalent U+5.50+ and two equivalent Sm3+ atoms to form a mixture of edge and corner-sharing OSm2U2 tetrahedra.