The structure described by SrCaI4 crystallizes in the monoclinic P2_1/c space group. Sr(1) is bonded to one I(1), one I(4), two equivalent I(2), and two equivalent I(3) atoms to form distorted SrI6 pentagonal pyramids that share corners with two equivalent Sr(1)I6 pentagonal pyramids,  an edgeedge with one Sr(1)I6 pentagonal pyramid, and edges with four equivalent Ca(1)I6 pentagonal pyramids. Ca(1) is bonded to one I(2), one I(3), two equivalent I(1), and two equivalent I(4) atoms to form distorted CaI6 pentagonal pyramids that share corners with two equivalent Ca(1)I6 pentagonal pyramids,  an edgeedge with one Ca(1)I6 pentagonal pyramid, and edges with four equivalent Sr(1)I6 pentagonal pyramids. There are four inequivalent I sites. In the first I site, I(1) is bonded in a distorted T-shaped geometry to one Sr(1) and two equivalent Ca(1) atoms. In the second I site, I(2) is bonded in a distorted T-shaped geometry to two equivalent Sr(1) and one Ca(1) atom. In the third I site, I(3) is bonded in a trigonal non-coplanar geometry to two equivalent Sr(1) and one Ca(1) atom. In the fourth I site, I(4) is bonded in a distorted T-shaped geometry to one Sr(1) and two equivalent Ca(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrCaI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.714
_cell_length_b   9.540
_cell_length_c   18.101
_cell_angle_alpha   59.981
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1153.368
_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  0.392  0.751  0.629  1.0
  Sr  Sr1  1  0.108  0.751  0.129  1.0
  Sr  Sr2  1  0.892  0.249  0.871  1.0
  Sr  Sr3  1  0.608  0.249  0.371  1.0
  Ca  Ca4  1  0.075  0.755  0.871  1.0
  Ca  Ca5  1  0.425  0.755  0.371  1.0
  Ca  Ca6  1  0.575  0.245  0.629  1.0
  Ca  Ca7  1  0.925  0.245  0.129  1.0
  I  I8  1  0.241  0.010  0.687  1.0
  I  I9  1  0.259  0.010  0.187  1.0
  I  I10  1  0.727  0.001  0.572  1.0
  I  I11  1  0.773  0.001  0.072  1.0
  I  I12  1  0.226  0.508  0.818  1.0
  I  I13  1  0.268  0.509  0.556  1.0
  I  I14  1  0.274  0.508  0.318  1.0
  I  I15  1  0.768  0.491  0.944  1.0
  I  I16  1  0.232  0.509  0.056  1.0
  I  I17  1  0.726  0.492  0.682  1.0
  I  I18  1  0.732  0.491  0.444  1.0
  I  I19  1  0.774  0.492  0.182  1.0
  I  I20  1  0.227  0.999  0.928  1.0
  I  I21  1  0.273  0.999  0.428  1.0
  I  I22  1  0.741  0.990  0.813  1.0
  I  I23  1  0.759  0.990  0.313  1.0
[/CIF]
.
The structure described by SrCaI4 crystallizes in the monoclinic P2_1/c space group. Sr(1) is bonded to one I(1), one I(4), two equivalent I(2), and two equivalent I(3) atoms to form distorted SrI6 pentagonal pyramids that share corners with two equivalent Sr(1)I6 pentagonal pyramids,  an edgeedge with one Sr(1)I6 pentagonal pyramid, and edges with four equivalent Ca(1)I6 pentagonal pyramids. Ca(1) is bonded to one I(2), one I(3), two equivalent I(1), and two equivalent I(4) atoms to form distorted CaI6 pentagonal pyramids that share corners with two equivalent Ca(1)I6 pentagonal pyramids,  an edgeedge with one Ca(1)I6 pentagonal pyramid, and edges with four equivalent Sr(1)I6 pentagonal pyramids. There are four inequivalent I sites. In the first I site, I(1) is bonded in a distorted T-shaped geometry to one Sr(1) and two equivalent Ca(1) atoms. In the second I site, I(2) is bonded in a distorted T-shaped geometry to two equivalent Sr(1) and one Ca(1) atom. In the third I site, I(3) is bonded in a trigonal non-coplanar geometry to two equivalent Sr(1) and one Ca(1) atom. In the fourth I site, I(4) is bonded in a distorted T-shaped geometry to one Sr(1) and two equivalent Ca(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrCaI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.714
_cell_length_b   9.540
_cell_length_c   18.101
_cell_angle_alpha   59.981
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1153.368
_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  0.392  0.751  0.629  1.0
  Sr  Sr1  1  0.108  0.751  0.129  1.0
  Sr  Sr2  1  0.892  0.249  0.871  1.0
  Sr  Sr3  1  0.608  0.249  0.371  1.0
  Ca  Ca4  1  0.075  0.755  0.871  1.0
  Ca  Ca5  1  0.425  0.755  0.371  1.0
  Ca  Ca6  1  0.575  0.245  0.629  1.0
  Ca  Ca7  1  0.925  0.245  0.129  1.0
  I  I8  1  0.241  0.010  0.687  1.0
  I  I9  1  0.259  0.010  0.187  1.0
  I  I10  1  0.727  0.001  0.572  1.0
  I  I11  1  0.773  0.001  0.072  1.0
  I  I12  1  0.226  0.508  0.818  1.0
  I  I13  1  0.268  0.509  0.556  1.0
  I  I14  1  0.274  0.508  0.318  1.0
  I  I15  1  0.768  0.491  0.944  1.0
  I  I16  1  0.232  0.509  0.056  1.0
  I  I17  1  0.726  0.492  0.682  1.0
  I  I18  1  0.732  0.491  0.444  1.0
  I  I19  1  0.774  0.492  0.182  1.0
  I  I20  1  0.227  0.999  0.928  1.0
  I  I21  1  0.273  0.999  0.428  1.0
  I  I22  1  0.741  0.990  0.813  1.0
  I  I23  1  0.759  0.990  0.313  1.0
[/CIF]
.