Materials Data on La2USe5 by Materials Project
ULa2Se5 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 2.81–3.05 Å. La3+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of La–Se bond distances ranging from 3.08–3.25 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent U4+ and two equivalent La3+ atoms to form distorted SeLa2U2 trigonal pyramids that share corners with six SeLa4U square pyramids, corners with two equivalent SeLa4U trigonal bipyramids, corners with six equivalent SeLa2U2 trigonal pyramids, edges with three SeLa4U square pyramids, edges with two equivalent SeLa4U trigonal bipyramids, and an edgeedge with one SeLa2U2 trigonal pyramid. In the second Se2- site, Se2- is bonded to one U4+ and four equivalent La3+ atoms to form distorted SeLa4U trigonal bipyramids that share corners with six SeLa4U square pyramids, corners with four equivalent SeLa4U trigonal bipyramids, corners with four equivalent SeLa2U2 trigonal pyramids, edges with six SeLa4U square pyramids, and edges with four equivalent SeLa2U2 trigonal pyramids. In the third Se2- site, Se2- is bonded to one U4+ and four equivalent La3+ atoms to form SeLa4U square pyramids that share corners with four equivalent SeLa4U square pyramids, corners with five equivalent SeLa4U trigonal bipyramids, corners with eight equivalent SeLa2U2 trigonal pyramids, edges with three SeLa4U square pyramids, edges with two equivalent SeLa4U trigonal bipyramids, edges with two equivalent SeLa2U2 trigonal pyramids, and a faceface with one SeLa4U square pyramid. In the fourth Se2- site, Se2- is bonded to one U4+ and four equivalent La3+ atoms to form distorted SeLa4U square pyramids that share corners with eight SeLa4U square pyramids, a cornercorner with one SeLa4U trigonal bipyramid, corners with four equivalent SeLa2U2 trigonal pyramids, an edgeedge with one SeLa4U square pyramid, edges with four equivalent SeLa4U trigonal bipyramids, edges with four equivalent SeLa2U2 trigonal pyramids, and a faceface with one SeLa4U square pyramid.