Materials Data on La2USe4 by Materials Project
ULa2Se4 crystallizes in the tetragonal I-42d space group. The structure is three-dimensional. U3+ is bonded to eight equivalent Se2- atoms to form distorted USe8 hexagonal bipyramids that share corners with eight equivalent LaSe8 hexagonal bipyramids, edges with four equivalent USe8 hexagonal bipyramids, and faces with eight equivalent LaSe8 hexagonal bipyramids. There are four shorter (3.02 Å) and four longer (3.13 Å) U–Se bond lengths. La+2.50+ is bonded to eight equivalent Se2- atoms to form distorted LaSe8 hexagonal bipyramids that share corners with four equivalent USe8 hexagonal bipyramids, corners with four equivalent LaSe8 hexagonal bipyramids, edges with four equivalent LaSe8 hexagonal bipyramids, faces with four equivalent USe8 hexagonal bipyramids, and faces with four equivalent LaSe8 hexagonal bipyramids. There are a spread of La–Se bond distances ranging from 3.04–3.23 Å. Se2- is bonded to two equivalent U3+ and four equivalent La+2.50+ atoms to form a mixture of distorted corner, edge, and face-sharing SeLa4U2 octahedra. The corner-sharing octahedra tilt angles range from 15–50°.