Materials Data on Sm2US5 by Materials Project

Abstract

USm2S5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. U4+ is bonded to seven S2- atoms to form distorted edge-sharing US7 pentagonal bipyramids. There are a spread of U–S bond distances ranging from 2.65–2.86 Å. Sm3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Sm–S bond distances ranging from 2.87–3.05 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent U4+ and two equivalent Sm3+ atoms to form distorted SSm2U2 trigonal pyramids that share corners with six SSm4U square pyramids, corners with two equivalent SSm4U trigonal bipyramids, corners with six equivalent SSm2U2 trigonal pyramids, edges with three SSm4U square pyramids, edges with two equivalent SSm4U trigonal bipyramids, and an edgeedge with one SSm2U2 trigonal pyramid. In the second S2- site, S2- is bonded to one U4+ and four equivalent Sm3+ atoms to form SSm4U square pyramids that share corners with four equivalent SSm4U square pyramids, corners with five equivalent SSm4U trigonal bipyramids, corners with eight equivalent SSm2U2 trigonal pyramids, edges with three SSm4U square pyramids, edges with two equivalent SSm4U trigonal bipyramids, edges with two equivalent SSm2U2 trigonal pyramids, and a faceface with one SSm4U square pyramid. In the third S2- site, S2- is bonded to one U4+ and four equivalent Sm3+ atoms to form distorted SSm4U square pyramids that share corners with eight SSm4U square pyramids, a cornercorner with one SSm4U trigonal bipyramid, corners with four equivalent SSm2U2 trigonal pyramids, an edgeedge with one SSm4U square pyramid, edges with four equivalent SSm4U trigonal bipyramids, edges with four equivalent SSm2U2 trigonal pyramids, and a faceface with one SSm4U square pyramid. In the fourth S2- site, S2- is bonded to one U4+ and four equivalent Sm3+ atoms to form distorted SSm4U trigonal bipyramids that share corners with six SSm4U square pyramids, corners with four equivalent SSm4U trigonal bipyramids, corners with four equivalent SSm2U2 trigonal pyramids, edges with six SSm4U square pyramids, and edges with four equivalent SSm2U2 trigonal pyramids.