Sr2Ca2IrO6 crystallizes in the monoclinic C2 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(5), one O(6), two equivalent O(2), and two equivalent O(4) atoms. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), two equivalent O(1), and two equivalent O(6) atoms. Ir(1) is bonded in an octahedral geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Sr(2), one Sr(3), one Ca(1), two equivalent Ca(3), and one Ir(1) atom to form distorted OSr2Ca3Ir octahedra that share  a cornercorner with one O(1)Sr2Ca3Ir octahedra,  a cornercorner with one O(6)Sr2Ca3Ir octahedra, corners with two equivalent O(2)Sr3Ca2Ir octahedra, corners with three equivalent O(4)Sr3Ca2Ir octahedra, corners with three equivalent O(5)Sr3Ca2Ir octahedra, corners with five equivalent O(3)Sr3Ca2Ir octahedra,  an edgeedge with one O(2)Sr3Ca2Ir octahedra,  an edgeedge with one O(4)Sr3Ca2Ir octahedra, edges with two equivalent O(6)Sr2Ca3Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(6)Sr2Ca3Ir octahedra,  a faceface with one O(2)Sr3Ca2Ir octahedra,  a faceface with one O(3)Sr3Ca2Ir octahedra, and  a faceface with one O(5)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 2-65°. In the second O site, O(2) is bonded to one Sr(1), two equivalent Sr(2), one Ca(1), one Ca(3), and one Ir(1) atom to form distorted OSr3Ca2Ir octahedra that share  a cornercorner with one O(4)Sr3Ca2Ir octahedra, corners with two equivalent O(1)Sr2Ca3Ir octahedra, corners with two equivalent O(3)Sr3Ca2Ir octahedra, corners with three equivalent O(6)Sr2Ca3Ir octahedra, corners with three equivalent O(5)Sr3Ca2Ir octahedra, corners with four equivalent O(2)Sr3Ca2Ir octahedra,  an edgeedge with one O(1)Sr2Ca3Ir octahedra,  an edgeedge with one O(6)Sr2Ca3Ir octahedra, edges with two equivalent O(4)Sr3Ca2Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra,  a faceface with one O(5)Sr3Ca2Ir octahedra, and faces with two equivalent O(3)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 1-65°. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Sr(3), one Ca(1), one Ca(3), and one Ir(1) atom to form distorted OSr3Ca2Ir octahedra that share  a cornercorner with one O(3)Sr3Ca2Ir octahedra,  a cornercorner with one O(5)Sr3Ca2Ir octahedra, corners with two equivalent O(2)Sr3Ca2Ir octahedra, corners with three equivalent O(6)Sr2Ca3Ir octahedra, corners with three equivalent O(4)Sr3Ca2Ir octahedra, corners with five equivalent O(1)Sr2Ca3Ir octahedra,  an edgeedge with one O(3)Sr3Ca2Ir octahedra, edges with three equivalent O(5)Sr3Ca2Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(6)Sr2Ca3Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra, and faces with two equivalent O(2)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 1-65°. In the fourth O site, O(4) is bonded to one Sr(1), two equivalent Sr(2), one Ca(2), one Ca(3), and one Ir(1) atom to form distorted OSr3Ca2Ir octahedra that share  a cornercorner with one O(2)Sr3Ca2Ir octahedra,  a cornercorner with one O(4)Sr3Ca2Ir octahedra, corners with two equivalent O(6)Sr2Ca3Ir octahedra, corners with three equivalent O(1)Sr2Ca3Ir octahedra, corners with three equivalent O(3)Sr3Ca2Ir octahedra, corners with five equivalent O(5)Sr3Ca2Ir octahedra,  an edgeedge with one O(1)Sr2Ca3Ir octahedra,  an edgeedge with one O(6)Sr2Ca3Ir octahedra, edges with two equivalent O(2)Sr3Ca2Ir octahedra,  a faceface with one O(6)Sr2Ca3Ir octahedra,  a faceface with one O(2)Sr3Ca2Ir octahedra,  a faceface with one O(3)Sr3Ca2Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra, and  a faceface with one O(5)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 2-65°. In the fifth O site, O(5) is bonded to one Sr(1), one Sr(2), one Sr(3), one Ca(2), one Ca(3), and one Ir(1) atom to form distorted OSr3Ca2Ir octahedra that share  a cornercorner with one O(3)Sr3Ca2Ir octahedra,  a cornercorner with one O(5)Sr3Ca2Ir octahedra, corners with two equivalent O(6)Sr2Ca3Ir octahedra, corners with three equivalent O(1)Sr2Ca3Ir octahedra, corners with three equivalent O(2)Sr3Ca2Ir octahedra, corners with five equivalent O(4)Sr3Ca2Ir octahedra,  an edgeedge with one O(5)Sr3Ca2Ir octahedra, edges with three equivalent O(3)Sr3Ca2Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(2)Sr3Ca2Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra, and faces with two equivalent O(6)Sr2Ca3Ir octahedra. The corner-sharing octahedral tilt angles range from 1-65°. In the sixth O site, O(6) is bonded to one Sr(2), one Sr(3), one Ca(2), two equivalent Ca(3), and one Ir(1) atom to form distorted OSr2Ca3Ir octahedra that share  a cornercorner with one O(1)Sr2Ca3Ir octahedra, corners with two equivalent O(4)Sr3Ca2Ir octahedra, corners with two equivalent O(5)Sr3Ca2Ir octahedra, corners with three equivalent O(2)Sr3Ca2Ir octahedra, corners with three equivalent O(3)Sr3Ca2Ir octahedra, corners with four equivalent O(6)Sr2Ca3Ir octahedra,  an edgeedge with one O(2)Sr3Ca2Ir octahedra,  an edgeedge with one O(4)Sr3Ca2Ir octahedra, edges with two equivalent O(1)Sr2Ca3Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(3)Sr3Ca2Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra, and faces with two equivalent O(5)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 1-65°.
Sr2Ca2IrO6 crystallizes in the monoclinic C2 space group. There are three inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. Both Sr(1)-O(2) bond lengths are 2.63 Å. Both Sr(1)-O(3) bond lengths are 2.53 Å. Both Sr(1)-O(4) bond lengths are 2.82 Å. Both Sr(1)-O(5) bond lengths are 2.65 Å. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(5), one O(6), two equivalent O(2), and two equivalent O(4) atoms. The Sr(2)-O(1) bond length is 2.62 Å. The Sr(2)-O(3) bond length is 2.79 Å. The Sr(2)-O(5) bond length is 2.59 Å. The Sr(2)-O(6) bond length is 2.52 Å. There is one shorter (2.64 Å) and one longer (2.76 Å) Sr(2)-O(2) bond length. There is one shorter (2.55 Å) and one longer (2.59 Å) Sr(2)-O(4) bond length. In the third Sr site, Sr(3) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms. Both Sr(3)-O(1) bond lengths are 2.76 Å. Both Sr(3)-O(3) bond lengths are 2.62 Å. Both Sr(3)-O(5) bond lengths are 2.52 Å. Both Sr(3)-O(6) bond lengths are 2.61 Å. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Ca(1)-O(1) bond lengths are 2.37 Å. Both Ca(1)-O(2) bond lengths are 2.34 Å. Both Ca(1)-O(3) bond lengths are 2.39 Å. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(5), and two equivalent O(6) atoms. Both Ca(2)-O(4) bond lengths are 2.33 Å. Both Ca(2)-O(5) bond lengths are 2.35 Å. Both Ca(2)-O(6) bond lengths are 2.35 Å. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), two equivalent O(1), and two equivalent O(6) atoms. The Ca(3)-O(2) bond length is 2.45 Å. The Ca(3)-O(3) bond length is 2.58 Å. The Ca(3)-O(4) bond length is 2.56 Å. The Ca(3)-O(5) bond length is 2.78 Å. There is one shorter (2.47 Å) and one longer (2.56 Å) Ca(3)-O(1) bond length. There is one shorter (2.58 Å) and one longer (2.84 Å) Ca(3)-O(6) bond length. Ir(1) is bonded in an octahedral geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Ir(1)-O(1) bond length is 2.07 Å. The Ir(1)-O(2) bond length is 2.09 Å. The Ir(1)-O(3) bond length is 2.05 Å. The Ir(1)-O(4) bond length is 2.06 Å. The Ir(1)-O(5) bond length is 2.05 Å. The Ir(1)-O(6) bond length is 2.04 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Sr(2), one Sr(3), one Ca(1), two equivalent Ca(3), and one Ir(1) atom to form distorted OSr2Ca3Ir octahedra that share  a cornercorner with one O(1)Sr2Ca3Ir octahedra,  a cornercorner with one O(6)Sr2Ca3Ir octahedra, corners with two equivalent O(2)Sr3Ca2Ir octahedra, corners with three equivalent O(4)Sr3Ca2Ir octahedra, corners with three equivalent O(5)Sr3Ca2Ir octahedra, corners with five equivalent O(3)Sr3Ca2Ir octahedra,  an edgeedge with one O(2)Sr3Ca2Ir octahedra,  an edgeedge with one O(4)Sr3Ca2Ir octahedra, edges with two equivalent O(6)Sr2Ca3Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(6)Sr2Ca3Ir octahedra,  a faceface with one O(2)Sr3Ca2Ir octahedra,  a faceface with one O(3)Sr3Ca2Ir octahedra, and  a faceface with one O(5)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 2-65°. In the second O site, O(2) is bonded to one Sr(1), two equivalent Sr(2), one Ca(1), one Ca(3), and one Ir(1) atom to form distorted OSr3Ca2Ir octahedra that share  a cornercorner with one O(4)Sr3Ca2Ir octahedra, corners with two equivalent O(1)Sr2Ca3Ir octahedra, corners with two equivalent O(3)Sr3Ca2Ir octahedra, corners with three equivalent O(6)Sr2Ca3Ir octahedra, corners with three equivalent O(5)Sr3Ca2Ir octahedra, corners with four equivalent O(2)Sr3Ca2Ir octahedra,  an edgeedge with one O(1)Sr2Ca3Ir octahedra,  an edgeedge with one O(6)Sr2Ca3Ir octahedra, edges with two equivalent O(4)Sr3Ca2Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra,  a faceface with one O(5)Sr3Ca2Ir octahedra, and faces with two equivalent O(3)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 1-65°. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Sr(3), one Ca(1), one Ca(3), and one Ir(1) atom to form distorted OSr3Ca2Ir octahedra that share  a cornercorner with one O(3)Sr3Ca2Ir octahedra,  a cornercorner with one O(5)Sr3Ca2Ir octahedra, corners with two equivalent O(2)Sr3Ca2Ir octahedra, corners with three equivalent O(6)Sr2Ca3Ir octahedra, corners with three equivalent O(4)Sr3Ca2Ir octahedra, corners with five equivalent O(1)Sr2Ca3Ir octahedra,  an edgeedge with one O(3)Sr3Ca2Ir octahedra, edges with three equivalent O(5)Sr3Ca2Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(6)Sr2Ca3Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra, and faces with two equivalent O(2)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 1-65°. In the fourth O site, O(4) is bonded to one Sr(1), two equivalent Sr(2), one Ca(2), one Ca(3), and one Ir(1) atom to form distorted OSr3Ca2Ir octahedra that share  a cornercorner with one O(2)Sr3Ca2Ir octahedra,  a cornercorner with one O(4)Sr3Ca2Ir octahedra, corners with two equivalent O(6)Sr2Ca3Ir octahedra, corners with three equivalent O(1)Sr2Ca3Ir octahedra, corners with three equivalent O(3)Sr3Ca2Ir octahedra, corners with five equivalent O(5)Sr3Ca2Ir octahedra,  an edgeedge with one O(1)Sr2Ca3Ir octahedra,  an edgeedge with one O(6)Sr2Ca3Ir octahedra, edges with two equivalent O(2)Sr3Ca2Ir octahedra,  a faceface with one O(6)Sr2Ca3Ir octahedra,  a faceface with one O(2)Sr3Ca2Ir octahedra,  a faceface with one O(3)Sr3Ca2Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra, and  a faceface with one O(5)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 2-65°. In the fifth O site, O(5) is bonded to one Sr(1), one Sr(2), one Sr(3), one Ca(2), one Ca(3), and one Ir(1) atom to form distorted OSr3Ca2Ir octahedra that share  a cornercorner with one O(3)Sr3Ca2Ir octahedra,  a cornercorner with one O(5)Sr3Ca2Ir octahedra, corners with two equivalent O(6)Sr2Ca3Ir octahedra, corners with three equivalent O(1)Sr2Ca3Ir octahedra, corners with three equivalent O(2)Sr3Ca2Ir octahedra, corners with five equivalent O(4)Sr3Ca2Ir octahedra,  an edgeedge with one O(5)Sr3Ca2Ir octahedra, edges with three equivalent O(3)Sr3Ca2Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(2)Sr3Ca2Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra, and faces with two equivalent O(6)Sr2Ca3Ir octahedra. The corner-sharing octahedral tilt angles range from 1-65°. In the sixth O site, O(6) is bonded to one Sr(2), one Sr(3), one Ca(2), two equivalent Ca(3), and one Ir(1) atom to form distorted OSr2Ca3Ir octahedra that share  a cornercorner with one O(1)Sr2Ca3Ir octahedra, corners with two equivalent O(4)Sr3Ca2Ir octahedra, corners with two equivalent O(5)Sr3Ca2Ir octahedra, corners with three equivalent O(2)Sr3Ca2Ir octahedra, corners with three equivalent O(3)Sr3Ca2Ir octahedra, corners with four equivalent O(6)Sr2Ca3Ir octahedra,  an edgeedge with one O(2)Sr3Ca2Ir octahedra,  an edgeedge with one O(4)Sr3Ca2Ir octahedra, edges with two equivalent O(1)Sr2Ca3Ir octahedra,  a faceface with one O(1)Sr2Ca3Ir octahedra,  a faceface with one O(3)Sr3Ca2Ir octahedra,  a faceface with one O(4)Sr3Ca2Ir octahedra, and faces with two equivalent O(5)Sr3Ca2Ir octahedra. The corner-sharing octahedral tilt angles range from 1-65°.