U2AsSe is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent As(1) and four equivalent Se(1) atoms to form UAs2Se4 octahedra that share corners with six equivalent U(1)As2Se4 octahedra, edges with four equivalent U(1)As2Se4 octahedra, and edges with eight equivalent U(2)As4Se2 octahedra. The corner-sharing octahedra are not tilted. In the second U site, U(2) is bonded to four equivalent As(1) and two equivalent Se(1) atoms to form UAs4Se2 octahedra that share corners with six equivalent U(2)As4Se2 octahedra, edges with four equivalent U(2)As4Se2 octahedra, and edges with eight equivalent U(1)As2Se4 octahedra. The corner-sharing octahedra are not tilted. As(1) is bonded to two equivalent U(1) and four equivalent U(2) atoms to form AsU6 octahedra that share corners with six equivalent As(1)U6 octahedra, edges with four equivalent As(1)U6 octahedra, and edges with eight equivalent Se(1)U6 octahedra. The corner-sharing octahedra are not tilted. Se(1) is bonded to two equivalent U(2) and four equivalent U(1) atoms to form SeU6 octahedra that share corners with six equivalent Se(1)U6 octahedra, edges with four equivalent Se(1)U6 octahedra, and edges with eight equivalent As(1)U6 octahedra. The corner-sharing octahedra are not tilted.
U2AsSe is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent As(1) and four equivalent Se(1) atoms to form UAs2Se4 octahedra that share corners with six equivalent U(1)As2Se4 octahedra, edges with four equivalent U(1)As2Se4 octahedra, and edges with eight equivalent U(2)As4Se2 octahedra. The corner-sharing octahedra are not tilted. Both U(1)-As(1) bond lengths are 2.96 Å. All U(1)-Se(1) bond lengths are 2.96 Å. In the second U site, U(2) is bonded to four equivalent As(1) and two equivalent Se(1) atoms to form UAs4Se2 octahedra that share corners with six equivalent U(2)As4Se2 octahedra, edges with four equivalent U(2)As4Se2 octahedra, and edges with eight equivalent U(1)As2Se4 octahedra. The corner-sharing octahedra are not tilted. All U(2)-As(1) bond lengths are 2.96 Å. Both U(2)-Se(1) bond lengths are 2.96 Å. As(1) is bonded to two equivalent U(1) and four equivalent U(2) atoms to form AsU6 octahedra that share corners with six equivalent As(1)U6 octahedra, edges with four equivalent As(1)U6 octahedra, and edges with eight equivalent Se(1)U6 octahedra. The corner-sharing octahedra are not tilted. Se(1) is bonded to two equivalent U(2) and four equivalent U(1) atoms to form SeU6 octahedra that share corners with six equivalent Se(1)U6 octahedra, edges with four equivalent Se(1)U6 octahedra, and edges with eight equivalent As(1)U6 octahedra. The corner-sharing octahedra are not tilted.