The crystal structure described by SrCa2I6 is Rutile-derived structured and crystallizes in the orthorhombic Pbcn space group. Sr(1) is bonded to two equivalent I(1), two equivalent I(2), and two equivalent I(3) atoms to form SrI6 octahedra that share corners with two equivalent Ca(2)I6 octahedra, corners with six equivalent Ca(1)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent I(3) and four equivalent I(1) atoms to form CaI6 octahedra that share corners with two equivalent Ca(2)I6 octahedra, corners with six equivalent Sr(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. In the second Ca site, Ca(2) is bonded to two equivalent I(3) and four equivalent I(2) atoms to form CaI6 octahedra that share corners with two equivalent Sr(1)I6 octahedra, corners with two equivalent Ca(1)I6 octahedra, corners with four equivalent Ca(2)I6 octahedra, and edges with two equivalent Sr(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 48-54°. There are three inequivalent I sites. In the first I site, I(1) is bonded in a trigonal planar geometry to one Sr(1) and two equivalent Ca(1) atoms. In the second I site, I(2) is bonded in a distorted trigonal planar geometry to one Sr(1) and two equivalent Ca(2) atoms. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to one Sr(1), one Ca(1), and one Ca(2) atom. is represented by the CIF file [CIF]
data_SrCa2I6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.298
_cell_length_b   8.094
_cell_length_c   27.060
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1598.397
_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  0.000  0.250  0.379  1.0
  Sr  Sr1  1  0.000  0.750  0.621  1.0
  Sr  Sr2  1  0.500  0.250  0.879  1.0
  Sr  Sr3  1  0.500  0.750  0.121  1.0
  Ca  Ca4  1  0.000  0.250  0.046  1.0
  Ca  Ca5  1  0.000  0.750  0.287  1.0
  Ca  Ca6  1  0.000  0.250  0.713  1.0
  Ca  Ca7  1  0.000  0.750  0.954  1.0
  Ca  Ca8  1  0.500  0.250  0.213  1.0
  Ca  Ca9  1  0.500  0.750  0.787  1.0
  Ca  Ca10  1  0.500  0.250  0.546  1.0
  Ca  Ca11  1  0.500  0.750  0.454  1.0
  I  I12  1  0.237  0.572  0.037  1.0
  I  I13  1  0.237  0.072  0.963  1.0
  I  I14  1  0.250  0.568  0.207  1.0
  I  I15  1  0.250  0.068  0.793  1.0
  I  I16  1  0.242  0.592  0.372  1.0
  I  I17  1  0.242  0.092  0.628  1.0
  I  I18  1  0.258  0.092  0.128  1.0
  I  I19  1  0.258  0.592  0.872  1.0
  I  I20  1  0.250  0.068  0.293  1.0
  I  I21  1  0.250  0.568  0.707  1.0
  I  I22  1  0.263  0.072  0.463  1.0
  I  I23  1  0.263  0.572  0.537  1.0
  I  I24  1  0.737  0.928  0.537  1.0
  I  I25  1  0.737  0.428  0.463  1.0
  I  I26  1  0.750  0.432  0.293  1.0
  I  I27  1  0.750  0.932  0.707  1.0
  I  I28  1  0.742  0.908  0.872  1.0
  I  I29  1  0.742  0.408  0.128  1.0
  I  I30  1  0.758  0.908  0.372  1.0
  I  I31  1  0.758  0.408  0.628  1.0
  I  I32  1  0.750  0.932  0.207  1.0
  I  I33  1  0.750  0.432  0.793  1.0
  I  I34  1  0.763  0.928  0.037  1.0
  I  I35  1  0.763  0.428  0.963  1.0
[/CIF]
.
The crystal structure described by SrCa2I6 is Rutile-derived structured and crystallizes in the orthorhombic Pbcn space group. Sr(1) is bonded to two equivalent I(1), two equivalent I(2), and two equivalent I(3) atoms to form SrI6 octahedra that share corners with two equivalent Ca(2)I6 octahedra, corners with six equivalent Ca(1)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 51-54°. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent I(3) and four equivalent I(1) atoms to form CaI6 octahedra that share corners with two equivalent Ca(2)I6 octahedra, corners with six equivalent Sr(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. In the second Ca site, Ca(2) is bonded to two equivalent I(3) and four equivalent I(2) atoms to form CaI6 octahedra that share corners with two equivalent Sr(1)I6 octahedra, corners with two equivalent Ca(1)I6 octahedra, corners with four equivalent Ca(2)I6 octahedra, and edges with two equivalent Sr(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 48-54°. There are three inequivalent I sites. In the first I site, I(1) is bonded in a trigonal planar geometry to one Sr(1) and two equivalent Ca(1) atoms. In the second I site, I(2) is bonded in a distorted trigonal planar geometry to one Sr(1) and two equivalent Ca(2) atoms. In the third I site, I(3) is bonded in a distorted trigonal planar geometry to one Sr(1), one Ca(1), and one Ca(2) atom. is represented by the CIF file [CIF]
data_SrCa2I6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.298
_cell_length_b   8.094
_cell_length_c   27.060
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   1598.397
_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  0.000  0.250  0.379  1.0
  Sr  Sr1  1  0.000  0.750  0.621  1.0
  Sr  Sr2  1  0.500  0.250  0.879  1.0
  Sr  Sr3  1  0.500  0.750  0.121  1.0
  Ca  Ca4  1  0.000  0.250  0.046  1.0
  Ca  Ca5  1  0.000  0.750  0.287  1.0
  Ca  Ca6  1  0.000  0.250  0.713  1.0
  Ca  Ca7  1  0.000  0.750  0.954  1.0
  Ca  Ca8  1  0.500  0.250  0.213  1.0
  Ca  Ca9  1  0.500  0.750  0.787  1.0
  Ca  Ca10  1  0.500  0.250  0.546  1.0
  Ca  Ca11  1  0.500  0.750  0.454  1.0
  I  I12  1  0.237  0.572  0.037  1.0
  I  I13  1  0.237  0.072  0.963  1.0
  I  I14  1  0.250  0.568  0.207  1.0
  I  I15  1  0.250  0.068  0.793  1.0
  I  I16  1  0.242  0.592  0.372  1.0
  I  I17  1  0.242  0.092  0.628  1.0
  I  I18  1  0.258  0.092  0.128  1.0
  I  I19  1  0.258  0.592  0.872  1.0
  I  I20  1  0.250  0.068  0.293  1.0
  I  I21  1  0.250  0.568  0.707  1.0
  I  I22  1  0.263  0.072  0.463  1.0
  I  I23  1  0.263  0.572  0.537  1.0
  I  I24  1  0.737  0.928  0.537  1.0
  I  I25  1  0.737  0.428  0.463  1.0
  I  I26  1  0.750  0.432  0.293  1.0
  I  I27  1  0.750  0.932  0.707  1.0
  I  I28  1  0.742  0.908  0.872  1.0
  I  I29  1  0.742  0.408  0.128  1.0
  I  I30  1  0.758  0.908  0.372  1.0
  I  I31  1  0.758  0.408  0.628  1.0
  I  I32  1  0.750  0.932  0.207  1.0
  I  I33  1  0.750  0.432  0.793  1.0
  I  I34  1  0.763  0.928  0.037  1.0
  I  I35  1  0.763  0.428  0.963  1.0
[/CIF]
.