The material structure described by 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°. is represented by the CIF file [CIF]
data_Sr2Ca2IrO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.794
_cell_length_b   6.794
_cell_length_c   6.756
_cell_angle_alpha   88.438
_cell_angle_beta   88.438
_cell_angle_gamma   91.013
_symmetry_Int_Tables_number   1
_cell_volume   311.607
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Sr  Sr0  1  0.114  0.886  0.000  1.0
  Sr  Sr1  1  0.614  0.749  0.863  1.0
  Sr  Sr2  1  0.885  0.115  0.500  1.0
  Sr  Sr3  1  0.251  0.386  0.137  1.0
  Ca  Ca4  1  0.749  0.251  0.000  1.0
  Ca  Ca5  1  0.251  0.749  0.500  1.0
  Ca  Ca6  1  0.749  0.609  0.361  1.0
  Ca  Ca7  1  0.391  0.251  0.639  1.0
  Ir  Ir8  1  0.501  0.002  0.251  1.0
  Ir  Ir9  1  0.998  0.499  0.749  1.0
  O  O10  1  0.579  0.292  0.307  1.0
  O  O11  1  0.450  0.084  0.957  1.0
  O  O12  1  0.787  0.944  0.173  1.0
  O  O13  1  0.288  0.572  0.797  1.0
  O  O14  1  0.946  0.785  0.667  1.0
  O  O15  1  0.076  0.451  0.461  1.0
  O  O16  1  0.428  0.712  0.203  1.0
  O  O17  1  0.549  0.924  0.539  1.0
  O  O18  1  0.215  0.054  0.333  1.0
  O  O19  1  0.708  0.421  0.693  1.0
  O  O20  1  0.056  0.213  0.827  1.0
  O  O21  1  0.916  0.550  0.043  1.0
[/CIF]
.
The material structure described by 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°. is represented by the CIF file [CIF]
data_Sr2Ca2IrO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.794
_cell_length_b   6.794
_cell_length_c   6.756
_cell_angle_alpha   88.438
_cell_angle_beta   88.438
_cell_angle_gamma   91.013
_symmetry_Int_Tables_number   1
_cell_volume   311.607
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Sr  Sr0  1  0.114  0.886  0.000  1.0
  Sr  Sr1  1  0.614  0.749  0.863  1.0
  Sr  Sr2  1  0.885  0.115  0.500  1.0
  Sr  Sr3  1  0.251  0.386  0.137  1.0
  Ca  Ca4  1  0.749  0.251  0.000  1.0
  Ca  Ca5  1  0.251  0.749  0.500  1.0
  Ca  Ca6  1  0.749  0.609  0.361  1.0
  Ca  Ca7  1  0.391  0.251  0.639  1.0
  Ir  Ir8  1  0.501  0.002  0.251  1.0
  Ir  Ir9  1  0.998  0.499  0.749  1.0
  O  O10  1  0.579  0.292  0.307  1.0
  O  O11  1  0.450  0.084  0.957  1.0
  O  O12  1  0.787  0.944  0.173  1.0
  O  O13  1  0.288  0.572  0.797  1.0
  O  O14  1  0.946  0.785  0.667  1.0
  O  O15  1  0.076  0.451  0.461  1.0
  O  O16  1  0.428  0.712  0.203  1.0
  O  O17  1  0.549  0.924  0.539  1.0
  O  O18  1  0.215  0.054  0.333  1.0
  O  O19  1  0.708  0.421  0.693  1.0
  O  O20  1  0.056  0.213  0.827  1.0
  O  O21  1  0.916  0.550  0.043  1.0
[/CIF]
.