The structure described by SrCaI4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one I(3), one I(4), two equivalent I(1), and two equivalent I(5) atoms to form SrI6 octahedra that share corners with two equivalent Ca(1)I6 octahedra, corners with two equivalent Ca(2)I6 octahedra,  an edgeedge with one Ca(1)I6 octahedra, edges with two equivalent Sr(2)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. In the second Sr site, Sr(2) is bonded to two equivalent I(2), two equivalent I(3), and two equivalent I(5) atoms to form SrI6 octahedra that share corners with two equivalent Ca(1)I6 octahedra, corners with two equivalent Ca(2)I6 octahedra,  an edgeedge with one Sr(2)I6 octahedra, edges with two equivalent Sr(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-18°. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one I(3), one I(4), two equivalent I(2), and two equivalent I(5) atoms to form CaI6 octahedra that share corners with two equivalent Sr(1)I6 octahedra, corners with two equivalent Sr(2)I6 octahedra,  an edgeedge with one Sr(1)I6 octahedra, edges with two equivalent Sr(2)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. In the second Ca site, Ca(2) is bonded to two equivalent I(1), two equivalent I(4), and two equivalent I(5) atoms to form CaI6 octahedra that share corners with two equivalent Sr(1)I6 octahedra, corners with two equivalent Sr(2)I6 octahedra,  an edgeedge with one Ca(2)I6 octahedra, edges with two equivalent Sr(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-18°. There are five inequivalent I sites. In the first I site, I(1) is bonded in a linear geometry to one Sr(1) and one Ca(2) atom. In the second I site, I(2) is bonded in a linear geometry to one Sr(2) and one Ca(1) atom. In the third I site, I(3) is bonded in a see-saw-like geometry to one Sr(1), two equivalent Sr(2), and one Ca(1) atom. In the fourth I site, I(4) is bonded in a see-saw-like geometry to one Sr(1), one Ca(1), and two equivalent Ca(2) atoms. In the fifth I site, I(5) is bonded in a see-saw-like geometry to one Sr(1), one Sr(2), one Ca(1), and one Ca(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrCaI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.357
_cell_length_b   10.357
_cell_length_c   13.063
_cell_angle_alpha   71.499
_cell_angle_beta   71.499
_cell_angle_gamma   84.096
_symmetry_Int_Tables_number   1
_cell_volume   1260.092
_cell_formula_units_Z   4
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  0.696  0.696  0.651  1.0
  Sr  Sr1  1  0.696  0.304  0.000  1.0
  Sr  Sr2  1  0.304  0.696  0.000  1.0
  Sr  Sr3  1  0.304  0.304  0.349  1.0
  Ca  Ca4  1  0.682  0.682  0.158  1.0
  Ca  Ca5  1  0.683  0.317  0.500  1.0
  Ca  Ca6  1  0.317  0.683  0.500  1.0
  Ca  Ca7  1  0.318  0.318  0.842  1.0
  I  I8  1  0.014  0.661  0.580  1.0
  I  I9  1  0.661  0.014  0.580  1.0
  I  I10  1  0.339  0.014  0.910  1.0
  I  I11  1  0.014  0.339  0.910  1.0
  I  I12  1  0.653  0.653  0.927  1.0
  I  I13  1  0.650  0.650  0.420  1.0
  I  I14  1  0.348  0.652  0.746  1.0
  I  I15  1  0.652  0.348  0.746  1.0
  I  I16  1  0.652  0.348  0.254  1.0
  I  I17  1  0.348  0.652  0.254  1.0
  I  I18  1  0.350  0.350  0.580  1.0
  I  I19  1  0.347  0.347  0.073  1.0
  I  I20  1  0.661  0.986  0.090  1.0
  I  I21  1  0.986  0.661  0.090  1.0
  I  I22  1  0.339  0.986  0.420  1.0
  I  I23  1  0.986  0.339  0.420  1.0
[/CIF]
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The structure described by SrCaI4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one I(3), one I(4), two equivalent I(1), and two equivalent I(5) atoms to form SrI6 octahedra that share corners with two equivalent Ca(1)I6 octahedra, corners with two equivalent Ca(2)I6 octahedra,  an edgeedge with one Ca(1)I6 octahedra, edges with two equivalent Sr(2)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. In the second Sr site, Sr(2) is bonded to two equivalent I(2), two equivalent I(3), and two equivalent I(5) atoms to form SrI6 octahedra that share corners with two equivalent Ca(1)I6 octahedra, corners with two equivalent Ca(2)I6 octahedra,  an edgeedge with one Sr(2)I6 octahedra, edges with two equivalent Sr(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-18°. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one I(3), one I(4), two equivalent I(2), and two equivalent I(5) atoms to form CaI6 octahedra that share corners with two equivalent Sr(1)I6 octahedra, corners with two equivalent Sr(2)I6 octahedra,  an edgeedge with one Sr(1)I6 octahedra, edges with two equivalent Sr(2)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-19°. In the second Ca site, Ca(2) is bonded to two equivalent I(1), two equivalent I(4), and two equivalent I(5) atoms to form CaI6 octahedra that share corners with two equivalent Sr(1)I6 octahedra, corners with two equivalent Sr(2)I6 octahedra,  an edgeedge with one Ca(2)I6 octahedra, edges with two equivalent Sr(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-18°. There are five inequivalent I sites. In the first I site, I(1) is bonded in a linear geometry to one Sr(1) and one Ca(2) atom. In the second I site, I(2) is bonded in a linear geometry to one Sr(2) and one Ca(1) atom. In the third I site, I(3) is bonded in a see-saw-like geometry to one Sr(1), two equivalent Sr(2), and one Ca(1) atom. In the fourth I site, I(4) is bonded in a see-saw-like geometry to one Sr(1), one Ca(1), and two equivalent Ca(2) atoms. In the fifth I site, I(5) is bonded in a see-saw-like geometry to one Sr(1), one Sr(2), one Ca(1), and one Ca(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrCaI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.357
_cell_length_b   10.357
_cell_length_c   13.063
_cell_angle_alpha   71.499
_cell_angle_beta   71.499
_cell_angle_gamma   84.096
_symmetry_Int_Tables_number   1
_cell_volume   1260.092
_cell_formula_units_Z   4
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  0.696  0.696  0.651  1.0
  Sr  Sr1  1  0.696  0.304  0.000  1.0
  Sr  Sr2  1  0.304  0.696  0.000  1.0
  Sr  Sr3  1  0.304  0.304  0.349  1.0
  Ca  Ca4  1  0.682  0.682  0.158  1.0
  Ca  Ca5  1  0.683  0.317  0.500  1.0
  Ca  Ca6  1  0.317  0.683  0.500  1.0
  Ca  Ca7  1  0.318  0.318  0.842  1.0
  I  I8  1  0.014  0.661  0.580  1.0
  I  I9  1  0.661  0.014  0.580  1.0
  I  I10  1  0.339  0.014  0.910  1.0
  I  I11  1  0.014  0.339  0.910  1.0
  I  I12  1  0.653  0.653  0.927  1.0
  I  I13  1  0.650  0.650  0.420  1.0
  I  I14  1  0.348  0.652  0.746  1.0
  I  I15  1  0.652  0.348  0.746  1.0
  I  I16  1  0.652  0.348  0.254  1.0
  I  I17  1  0.348  0.652  0.254  1.0
  I  I18  1  0.350  0.350  0.580  1.0
  I  I19  1  0.347  0.347  0.073  1.0
  I  I20  1  0.661  0.986  0.090  1.0
  I  I21  1  0.986  0.661  0.090  1.0
  I  I22  1  0.339  0.986  0.420  1.0
  I  I23  1  0.986  0.339  0.420  1.0
[/CIF]
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