Sr2CuO2Br crystallizes in the trigonal R-3m space group. Sr(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent O(1) and three equivalent Br(1) atoms. Cu(1) is bonded in a linear geometry to two equivalent O(1) atoms. O(1) is bonded to three equivalent Sr(1) and one Cu(1) atom to form OSr3Cu tetrahedra that share corners with three equivalent Br(1)Sr6 octahedra, corners with seven equivalent O(1)Sr3Cu tetrahedra, and edges with three equivalent Br(1)Sr6 octahedra. The corner-sharing octahedral tilt angles are 29°. Br(1) is bonded to six equivalent Sr(1) atoms to form distorted BrSr6 octahedra that share corners with six equivalent O(1)Sr3Cu tetrahedra, edges with six equivalent Br(1)Sr6 octahedra, and edges with six equivalent O(1)Sr3Cu tetrahedra.
Sr2CuO2Br crystallizes in the trigonal R-3m space group. Sr(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent O(1) and three equivalent Br(1) atoms. All Sr(1)-O(1) bond lengths are 2.42 Å. All Sr(1)-Br(1) bond lengths are 3.27 Å. Cu(1) is bonded in a linear geometry to two equivalent O(1) atoms. Both Cu(1)-O(1) bond lengths are 1.80 Å. O(1) is bonded to three equivalent Sr(1) and one Cu(1) atom to form OSr3Cu tetrahedra that share corners with three equivalent Br(1)Sr6 octahedra, corners with seven equivalent O(1)Sr3Cu tetrahedra, and edges with three equivalent Br(1)Sr6 octahedra. The corner-sharing octahedral tilt angles are 29°. Br(1) is bonded to six equivalent Sr(1) atoms to form distorted BrSr6 octahedra that share corners with six equivalent O(1)Sr3Cu tetrahedra, edges with six equivalent Br(1)Sr6 octahedra, and edges with six equivalent O(1)Sr3Cu tetrahedra.