The material described by Sr2CaI6 crystallizes in the orthorhombic Cmce space group. Sr(1) is bonded in a body-centered cubic geometry to four equivalent I(1) and four equivalent I(2) atoms. Ca(1) is bonded in a square co-planar geometry to four equivalent I(1) atoms. There are two 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 to four equivalent Sr(1) atoms to form a mixture of corner and edge-sharing ISr4 tetrahedra. is represented by the CIF file [CIF]
data_Sr2CaI6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.696
_cell_length_b   12.696
_cell_length_c   8.033
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   142.968
_symmetry_Int_Tables_number   1
_cell_volume   779.820
_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  0.333  0.667  0.500  1.0
  Sr  Sr1  1  0.167  0.833  0.000  1.0
  Sr  Sr2  1  0.667  0.333  0.500  1.0
  Sr  Sr3  1  0.833  0.167  0.000  1.0
  Ca  Ca4  1  0.000  0.000  0.500  1.0
  Ca  Ca5  1  0.500  0.500  0.000  1.0
  I  I6  1  0.712  0.883  0.294  1.0
  I  I7  1  0.519  0.019  0.750  1.0
  I  I8  1  0.617  0.788  0.794  1.0
  I  I9  1  0.212  0.383  0.206  1.0
  I  I10  1  0.883  0.712  0.294  1.0
  I  I11  1  0.981  0.481  0.250  1.0
  I  I12  1  0.019  0.519  0.750  1.0
  I  I13  1  0.788  0.617  0.794  1.0
  I  I14  1  0.117  0.288  0.706  1.0
  I  I15  1  0.383  0.212  0.206  1.0
  I  I16  1  0.481  0.981  0.250  1.0
  I  I17  1  0.288  0.117  0.706  1.0
[/CIF]
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The material described by Sr2CaI6 crystallizes in the orthorhombic Cmce space group. Sr(1) is bonded in a body-centered cubic geometry to four equivalent I(1) and four equivalent I(2) atoms. Ca(1) is bonded in a square co-planar geometry to four equivalent I(1) atoms. There are two 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 to four equivalent Sr(1) atoms to form a mixture of corner and edge-sharing ISr4 tetrahedra. is represented by the CIF file [CIF]
data_Sr2CaI6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.696
_cell_length_b   12.696
_cell_length_c   8.033
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   142.968
_symmetry_Int_Tables_number   1
_cell_volume   779.820
_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  0.333  0.667  0.500  1.0
  Sr  Sr1  1  0.167  0.833  0.000  1.0
  Sr  Sr2  1  0.667  0.333  0.500  1.0
  Sr  Sr3  1  0.833  0.167  0.000  1.0
  Ca  Ca4  1  0.000  0.000  0.500  1.0
  Ca  Ca5  1  0.500  0.500  0.000  1.0
  I  I6  1  0.712  0.883  0.294  1.0
  I  I7  1  0.519  0.019  0.750  1.0
  I  I8  1  0.617  0.788  0.794  1.0
  I  I9  1  0.212  0.383  0.206  1.0
  I  I10  1  0.883  0.712  0.294  1.0
  I  I11  1  0.981  0.481  0.250  1.0
  I  I12  1  0.019  0.519  0.750  1.0
  I  I13  1  0.788  0.617  0.794  1.0
  I  I14  1  0.117  0.288  0.706  1.0
  I  I15  1  0.383  0.212  0.206  1.0
  I  I16  1  0.481  0.981  0.250  1.0
  I  I17  1  0.288  0.117  0.706  1.0
[/CIF]
.