The structure described by SrCa2I6 is Hydrophilite-derived structured and crystallizes in the monoclinic C2/c space group. Sr(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form distorted SrI6 pentagonal pyramids that share corners with four equivalent Ca(1)I6 octahedra, edges with two equivalent Ca(1)I6 octahedra, and edges with two equivalent Sr(1)I6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 40-57°. Ca(1) is bonded to one I(1), two equivalent I(2), and three equivalent I(3) atoms to form CaI6 octahedra that share corners with six equivalent Ca(1)I6 octahedra, corners with two equivalent Sr(1)I6 pentagonal pyramids,  an edgeedge with one Ca(1)I6 octahedra, and  an edgeedge with one Sr(1)I6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 45-62°. There are three inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ca(1) atom. In the second I site, I(2) is bonded in a trigonal planar geometry to one Sr(1) and two equivalent Ca(1) atoms. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to three equivalent Ca(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrCa2I6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.114
_cell_length_b   13.114
_cell_length_c   8.645
_cell_angle_alpha   84.827
_cell_angle_beta   84.827
_cell_angle_gamma   33.724
_symmetry_Int_Tables_number   1
_cell_volume   821.805
_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  0.730  0.270  0.750  1.0
  Sr  Sr1  1  0.270  0.730  0.250  1.0
  Ca  Ca2  1  0.055  0.602  0.629  1.0
  Ca  Ca3  1  0.602  0.055  0.129  1.0
  Ca  Ca4  1  0.398  0.945  0.871  1.0
  Ca  Ca5  1  0.945  0.398  0.371  1.0
  I  I6  1  0.372  0.489  0.575  1.0
  I  I7  1  0.489  0.372  0.075  1.0
  I  I8  1  0.906  0.883  0.871  1.0
  I  I9  1  0.883  0.906  0.371  1.0
  I  I10  1  0.318  0.244  0.860  1.0
  I  I11  1  0.244  0.318  0.360  1.0
  I  I12  1  0.756  0.682  0.640  1.0
  I  I13  1  0.682  0.756  0.140  1.0
  I  I14  1  0.117  0.094  0.629  1.0
  I  I15  1  0.094  0.117  0.129  1.0
  I  I16  1  0.511  0.628  0.925  1.0
  I  I17  1  0.628  0.511  0.425  1.0
[/CIF]
.
The structure described by SrCa2I6 is Hydrophilite-derived structured and crystallizes in the monoclinic C2/c space group. Sr(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form distorted SrI6 pentagonal pyramids that share corners with four equivalent Ca(1)I6 octahedra, edges with two equivalent Ca(1)I6 octahedra, and edges with two equivalent Sr(1)I6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 40-57°. Ca(1) is bonded to one I(1), two equivalent I(2), and three equivalent I(3) atoms to form CaI6 octahedra that share corners with six equivalent Ca(1)I6 octahedra, corners with two equivalent Sr(1)I6 pentagonal pyramids,  an edgeedge with one Ca(1)I6 octahedra, and  an edgeedge with one Sr(1)I6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 45-62°. There are three inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ca(1) atom. In the second I site, I(2) is bonded in a trigonal planar geometry to one Sr(1) and two equivalent Ca(1) atoms. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to three equivalent Ca(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrCa2I6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.114
_cell_length_b   13.114
_cell_length_c   8.645
_cell_angle_alpha   84.827
_cell_angle_beta   84.827
_cell_angle_gamma   33.724
_symmetry_Int_Tables_number   1
_cell_volume   821.805
_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  0.730  0.270  0.750  1.0
  Sr  Sr1  1  0.270  0.730  0.250  1.0
  Ca  Ca2  1  0.055  0.602  0.629  1.0
  Ca  Ca3  1  0.602  0.055  0.129  1.0
  Ca  Ca4  1  0.398  0.945  0.871  1.0
  Ca  Ca5  1  0.945  0.398  0.371  1.0
  I  I6  1  0.372  0.489  0.575  1.0
  I  I7  1  0.489  0.372  0.075  1.0
  I  I8  1  0.906  0.883  0.871  1.0
  I  I9  1  0.883  0.906  0.371  1.0
  I  I10  1  0.318  0.244  0.860  1.0
  I  I11  1  0.244  0.318  0.360  1.0
  I  I12  1  0.756  0.682  0.640  1.0
  I  I13  1  0.682  0.756  0.140  1.0
  I  I14  1  0.117  0.094  0.629  1.0
  I  I15  1  0.094  0.117  0.129  1.0
  I  I16  1  0.511  0.628  0.925  1.0
  I  I17  1  0.628  0.511  0.425  1.0
[/CIF]
.