Materials Data on ErUN2 by Materials Project
UErN2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. U3+ is bonded to six N3- atoms to form UN6 octahedra that share corners with six equivalent UN6 octahedra, edges with four equivalent UN6 octahedra, and edges with eight equivalent ErN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.41 Å) and four longer (2.43 Å) U–N bond lengths. Er3+ is bonded to six N3- atoms to form ErN6 octahedra that share corners with six equivalent ErN6 octahedra, edges with four equivalent ErN6 octahedra, and edges with eight equivalent UN6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.41 Å) and four longer (2.43 Å) Er–N bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to two equivalent U3+ and four equivalent Er3+ atoms to form a mixture of corner and edge-sharing NEr4U2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second N3- site, N3- is bonded to four equivalent U3+ and two equivalent Er3+ atoms to form NEr2U4 octahedra that share corners with six equivalent NEr2U4 octahedra and edges with twelve NEr4U2 octahedra. The corner-sharing octahedral tilt angles are 0°.