Sr5Ir3O11 is (La,Ba)CuO4-like structured and crystallizes in the monoclinic C2 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(5), two equivalent O(6), and four equivalent O(3) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(2), and four equivalent O(4) atoms. In the third Sr site, Sr(3) is bonded to four equivalent O(1), four equivalent O(5), and four equivalent O(6) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(3)O12 cuboctahedra, faces with four equivalent Sr(3)O12 cuboctahedra, and faces with eight equivalent Ir(2)O6 octahedra. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form corner-sharing IrO6 octahedra. The corner-sharing octahedral tilt angles are 5°. In the second Ir site, Ir(2) is bonded to one O(1), one O(3), two equivalent O(5), and two equivalent O(6) atoms to form IrO6 octahedra that share corners with five equivalent Ir(2)O6 octahedra and faces with four equivalent Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-12°. There are six inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(3) and two equivalent Ir(2) atoms to form distorted OSr4Ir2 octahedra that share corners with two equivalent O(3)Sr5Ir octahedra, corners with four equivalent O(1)Sr4Ir2 octahedra, and edges with four equivalent O(1)Sr4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Sr(1), four equivalent Sr(2), and one Ir(1) atom to form distorted OSr5Ir octahedra that share corners with five equivalent O(2)Sr5Ir octahedra, corners with eight equivalent O(4)Sr4Ir2 octahedra, edges with four equivalent O(2)Sr5Ir octahedra, edges with four equivalent O(3)Sr5Ir octahedra, and faces with four equivalent O(4)Sr4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 1-57°. In the third O site, O(3) is bonded to one Sr(2), four equivalent Sr(1), and one Ir(2) atom to form distorted OSr5Ir octahedra that share  a cornercorner with one O(1)Sr4Ir2 octahedra, corners with four equivalent O(4)Sr4Ir2 octahedra, corners with four equivalent O(3)Sr5Ir octahedra, edges with four equivalent O(2)Sr5Ir octahedra, and edges with four equivalent O(3)Sr5Ir octahedra. The corner-sharing octahedral tilt angles range from 1-47°. In the fourth O site, O(4) is bonded to four equivalent Sr(2) and two equivalent Ir(1) atoms to form distorted OSr4Ir2 octahedra that share corners with two equivalent O(4)Sr4Ir2 octahedra, corners with four equivalent O(3)Sr5Ir octahedra, corners with eight equivalent O(2)Sr5Ir octahedra, edges with two equivalent O(4)Sr4Ir2 octahedra, faces with four equivalent O(4)Sr4Ir2 octahedra, and faces with four equivalent O(2)Sr5Ir octahedra. The corner-sharing octahedral tilt angles range from 5-57°. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Ir(2) atoms. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Ir(2) atoms.
Sr5Ir3O11 is (La,Ba)CuO4-like structured and crystallizes in the monoclinic C2 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(5), two equivalent O(6), and four equivalent O(3) atoms. The Sr(1)-O(2) bond length is 2.45 Å. There is one shorter (2.59 Å) and one longer (2.83 Å) Sr(1)-O(5) bond length. There is one shorter (2.60 Å) and one longer (2.81 Å) Sr(1)-O(6) bond length. There are a spread of Sr(1)-O(3) bond distances ranging from 2.72-2.87 Å. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(3), four equivalent O(2), and four equivalent O(4) atoms. The Sr(2)-O(3) bond length is 2.44 Å. There are a spread of Sr(2)-O(2) bond distances ranging from 2.79-2.89 Å. There are a spread of Sr(2)-O(4) bond distances ranging from 2.66-2.78 Å. In the third Sr site, Sr(3) is bonded to four equivalent O(1), four equivalent O(5), and four equivalent O(6) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(3)O12 cuboctahedra, faces with four equivalent Sr(3)O12 cuboctahedra, and faces with eight equivalent Ir(2)O6 octahedra. There are two shorter (2.79 Å) and two longer (2.83 Å) Sr(3)-O(1) bond lengths. There are two shorter (2.68 Å) and two longer (3.00 Å) Sr(3)-O(5) bond lengths. There are two shorter (2.68 Å) and two longer (3.01 Å) Sr(3)-O(6) bond lengths. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form corner-sharing IrO6 octahedra. The corner-sharing octahedral tilt angles are 5°. Both Ir(1)-O(2) bond lengths are 2.08 Å. There are two shorter (1.98 Å) and two longer (2.00 Å) Ir(1)-O(4) bond lengths. In the second Ir site, Ir(2) is bonded to one O(1), one O(3), two equivalent O(5), and two equivalent O(6) atoms to form IrO6 octahedra that share corners with five equivalent Ir(2)O6 octahedra and faces with four equivalent Sr(3)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-12°. The Ir(2)-O(1) bond length is 2.06 Å. The Ir(2)-O(3) bond length is 2.03 Å. There is one shorter (1.98 Å) and one longer (2.01 Å) Ir(2)-O(5) bond length. There is one shorter (1.98 Å) and one longer (2.02 Å) Ir(2)-O(6) bond length. There are six inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(3) and two equivalent Ir(2) atoms to form distorted OSr4Ir2 octahedra that share corners with two equivalent O(3)Sr5Ir octahedra, corners with four equivalent O(1)Sr4Ir2 octahedra, and edges with four equivalent O(1)Sr4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second O site, O(2) is bonded to one Sr(1), four equivalent Sr(2), and one Ir(1) atom to form distorted OSr5Ir octahedra that share corners with five equivalent O(2)Sr5Ir octahedra, corners with eight equivalent O(4)Sr4Ir2 octahedra, edges with four equivalent O(2)Sr5Ir octahedra, edges with four equivalent O(3)Sr5Ir octahedra, and faces with four equivalent O(4)Sr4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 1-57°. In the third O site, O(3) is bonded to one Sr(2), four equivalent Sr(1), and one Ir(2) atom to form distorted OSr5Ir octahedra that share  a cornercorner with one O(1)Sr4Ir2 octahedra, corners with four equivalent O(4)Sr4Ir2 octahedra, corners with four equivalent O(3)Sr5Ir octahedra, edges with four equivalent O(2)Sr5Ir octahedra, and edges with four equivalent O(3)Sr5Ir octahedra. The corner-sharing octahedral tilt angles range from 1-47°. In the fourth O site, O(4) is bonded to four equivalent Sr(2) and two equivalent Ir(1) atoms to form distorted OSr4Ir2 octahedra that share corners with two equivalent O(4)Sr4Ir2 octahedra, corners with four equivalent O(3)Sr5Ir octahedra, corners with eight equivalent O(2)Sr5Ir octahedra, edges with two equivalent O(4)Sr4Ir2 octahedra, faces with four equivalent O(4)Sr4Ir2 octahedra, and faces with four equivalent O(2)Sr5Ir octahedra. The corner-sharing octahedral tilt angles range from 5-57°. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Ir(2) atoms. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(3), and two equivalent Ir(2) atoms.