CuAsSe crystallizes in the orthorhombic Pnma space group. Cu(1) is bonded to one As(1) and three equivalent Se(1) atoms to form CuAsSe3 tetrahedra that share  a cornercorner with one Se(1)Cu3As tetrahedra and corners with six equivalent Cu(1)AsSe3 tetrahedra. As(1) is bonded in a 4-coordinate geometry to one Cu(1), two equivalent As(1), and one Se(1) atom. Se(1) is bonded to three equivalent Cu(1) and one As(1) atom to form SeCu3As tetrahedra that share  a cornercorner with one Cu(1)AsSe3 tetrahedra and corners with six equivalent Se(1)Cu3As tetrahedra.
CuAsSe crystallizes in the orthorhombic Pnma space group. Cu(1) is bonded to one As(1) and three equivalent Se(1) atoms to form CuAsSe3 tetrahedra that share  a cornercorner with one Se(1)Cu3As tetrahedra and corners with six equivalent Cu(1)AsSe3 tetrahedra. The Cu(1)-As(1) bond length is 2.34 Å. All Cu(1)-Se(1) bond lengths are 2.40 Å. As(1) is bonded in a 4-coordinate geometry to one Cu(1), two equivalent As(1), and one Se(1) atom. Both As(1)-As(1) bond lengths are 2.54 Å. The As(1)-Se(1) bond length is 2.42 Å. Se(1) is bonded to three equivalent Cu(1) and one As(1) atom to form SeCu3As tetrahedra that share  a cornercorner with one Cu(1)AsSe3 tetrahedra and corners with six equivalent Se(1)Cu3As tetrahedra.