The structure described by Sr2CaI6 is Rutile-derived structured and crystallizes in the tetragonal P4_2/mnm space group. Sr(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form SrI6 octahedra that share corners with four equivalent Sr(1)I6 octahedra, corners with four equivalent Ca(1)I6 octahedra,  an edgeedge with one Sr(1)I6 octahedra, and  an edgeedge with one Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 46-52°. Ca(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form CaI6 octahedra that share corners with eight equivalent Sr(1)I6 octahedra and edges with two equivalent Sr(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 46-48°. There are two inequivalent I sites. In the first I site, I(2) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ca(1) atom. In the second I site, I(1) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ca(1) atom. is represented by the CIF card [CIF]
data_Sr2CaI6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.662
_cell_length_b   7.662
_cell_length_c   14.624
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   858.531
_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  0.000  0.000  0.334  1.0
  Sr  Sr1  1  0.000  0.000  0.666  1.0
  Sr  Sr2  1  0.500  0.500  0.166  1.0
  Sr  Sr3  1  0.500  0.500  0.834  1.0
  Ca  Ca4  1  0.000  0.000  0.000  1.0
  Ca  Ca5  1  0.500  0.500  0.500  1.0
  I  I6  1  0.194  0.806  0.160  1.0
  I  I7  1  0.194  0.806  0.840  1.0
  I  I8  1  0.205  0.795  0.500  1.0
  I  I9  1  0.295  0.295  0.000  1.0
  I  I10  1  0.306  0.306  0.340  1.0
  I  I11  1  0.306  0.306  0.660  1.0
  I  I12  1  0.694  0.694  0.340  1.0
  I  I13  1  0.694  0.694  0.660  1.0
  I  I14  1  0.705  0.705  0.000  1.0
  I  I15  1  0.795  0.205  0.500  1.0
  I  I16  1  0.806  0.194  0.160  1.0
  I  I17  1  0.806  0.194  0.840  1.0
[/CIF]
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The structure described by Sr2CaI6 is Rutile-derived structured and crystallizes in the tetragonal P4_2/mnm space group. Sr(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form SrI6 octahedra that share corners with four equivalent Sr(1)I6 octahedra, corners with four equivalent Ca(1)I6 octahedra,  an edgeedge with one Sr(1)I6 octahedra, and  an edgeedge with one Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 46-52°. Ca(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form CaI6 octahedra that share corners with eight equivalent Sr(1)I6 octahedra and edges with two equivalent Sr(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 46-48°. There are two inequivalent I sites. In the first I site, I(2) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ca(1) atom. In the second I site, I(1) is bonded in a distorted trigonal planar geometry to two equivalent Sr(1) and one Ca(1) atom. is represented by the CIF card [CIF]
data_Sr2CaI6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.662
_cell_length_b   7.662
_cell_length_c   14.624
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   858.531
_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  0.000  0.000  0.334  1.0
  Sr  Sr1  1  0.000  0.000  0.666  1.0
  Sr  Sr2  1  0.500  0.500  0.166  1.0
  Sr  Sr3  1  0.500  0.500  0.834  1.0
  Ca  Ca4  1  0.000  0.000  0.000  1.0
  Ca  Ca5  1  0.500  0.500  0.500  1.0
  I  I6  1  0.194  0.806  0.160  1.0
  I  I7  1  0.194  0.806  0.840  1.0
  I  I8  1  0.205  0.795  0.500  1.0
  I  I9  1  0.295  0.295  0.000  1.0
  I  I10  1  0.306  0.306  0.340  1.0
  I  I11  1  0.306  0.306  0.660  1.0
  I  I12  1  0.694  0.694  0.340  1.0
  I  I13  1  0.694  0.694  0.660  1.0
  I  I14  1  0.705  0.705  0.000  1.0
  I  I15  1  0.795  0.205  0.500  1.0
  I  I16  1  0.806  0.194  0.160  1.0
  I  I17  1  0.806  0.194  0.840  1.0
[/CIF]
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