Materials Data on Ce2USe5 by Materials Project

Abstract

UCe2Se5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. U4+ is bonded to seven Se2- atoms to form distorted edge-sharing USe7 pentagonal bipyramids. There are a spread of U–Se bond distances ranging from 2.82–3.02 Å. Ce3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Ce–Se bond distances ranging from 3.03–3.19 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one U4+ and four equivalent Ce3+ atoms to form distorted SeCe4U square pyramids that share corners with eight SeCe4U square pyramids, a cornercorner with one SeCe4U trigonal bipyramid, corners with four equivalent SeCe2U2 trigonal pyramids, an edgeedge with one SeCe4U square pyramid, edges with four equivalent SeCe4U trigonal bipyramids, edges with four equivalent SeCe2U2 trigonal pyramids, and a faceface with one SeCe4U square pyramid. In the second Se2- site, Se2- is bonded to one U4+ and four equivalent Ce3+ atoms to form SeCe4U square pyramids that share corners with four equivalent SeCe4U square pyramids, corners with five equivalent SeCe4U trigonal bipyramids, corners with eight equivalent SeCe2U2 trigonal pyramids, edges with three SeCe4U square pyramids, edges with two equivalent SeCe4U trigonal bipyramids, edges with two equivalent SeCe2U2 trigonal pyramids, and a faceface with one SeCe4U square pyramid. In the third Se2- site, Se2- is bonded to one U4+ and four equivalent Ce3+ atoms to form distorted SeCe4U trigonal bipyramids that share corners with six SeCe4U square pyramids, corners with four equivalent SeCe4U trigonal bipyramids, corners with four equivalent SeCe2U2 trigonal pyramids, edges with six SeCe4U square pyramids, and edges with four equivalent SeCe2U2 trigonal pyramids. In the fourth Se2- site, Se2- is bonded to two equivalent U4+ and two equivalent Ce3+ atoms to form distorted SeCe2U2 trigonal pyramids that share corners with six SeCe4U square pyramids, corners with two equivalent SeCe4U trigonal bipyramids, corners with six equivalent SeCe2U2 trigonal pyramids, edges with three SeCe4U square pyramids, edges with two equivalent SeCe4U trigonal bipyramids, and an edgeedge with one SeCe2U2 trigonal pyramid.