Materials Data on Sm2USe5 by Materials Project

Abstract

USm2Se5 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 2.79–3.00 Å. Sm3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Sm–Se bond distances ranging from 3.02–3.18 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent U4+ and two equivalent Sm3+ atoms. In the second Se2- site, Se2- is bonded to one U4+ and four equivalent Sm3+ atoms to form a mixture of distorted corner and edge-sharing SeSm4U trigonal bipyramids. In the third Se2- site, Se2- is bonded to one U4+ and four equivalent Sm3+ atoms to form a mixture of corner, edge, and face-sharing SeSm4U square pyramids. In the fourth Se2- site, Se2- is bonded to one U4+ and four equivalent Sm3+ atoms to form a mixture of distorted corner, edge, and face-sharing SeSm4U square pyramids.