The structure described by BaSr2I6 crystallizes in the monoclinic C2/c space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent I(1), two equivalent I(2), and four equivalent I(3) atoms. Sr(1) is bonded to two equivalent I(1), two equivalent I(2), and two equivalent I(3) atoms to form distorted edge-sharing SrI6 pentagonal pyramids. There are three inequivalent I sites. In the first I site, I(1) is bonded in a T-shaped geometry to one Ba(1) and two equivalent Sr(1) atoms. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one Ba(1) and two equivalent Sr(1) atoms. In the third I site, I(3) is bonded to two equivalent Ba(1) and two equivalent Sr(1) atoms to form a mixture of distorted corner and edge-sharing IBa2Sr2 trigonal pyramids. is represented by the CIF file [CIF]
data_BaSr2I6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.974
_cell_length_b   8.974
_cell_length_c   11.921
_cell_angle_alpha   87.082
_cell_angle_beta   87.082
_cell_angle_gamma   119.301
_symmetry_Int_Tables_number   1
_cell_volume   832.996
_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
  Ba  Ba0  1  0.032  0.968  0.750  1.0
  Ba  Ba1  1  0.968  0.032  0.250  1.0
  Sr  Sr2  1  0.394  0.704  0.445  1.0
  Sr  Sr3  1  0.296  0.606  0.055  1.0
  Sr  Sr4  1  0.704  0.394  0.945  1.0
  Sr  Sr5  1  0.606  0.296  0.555  1.0
  I  I6  1  0.610  0.697  0.866  1.0
  I  I7  1  0.452  0.066  0.805  1.0
  I  I8  1  0.242  0.978  0.467  1.0
  I  I9  1  0.022  0.758  0.033  1.0
  I  I10  1  0.934  0.548  0.695  1.0
  I  I11  1  0.303  0.390  0.634  1.0
  I  I12  1  0.697  0.610  0.366  1.0
  I  I13  1  0.066  0.452  0.305  1.0
  I  I14  1  0.978  0.242  0.967  1.0
  I  I15  1  0.758  0.022  0.533  1.0
  I  I16  1  0.548  0.934  0.195  1.0
  I  I17  1  0.390  0.303  0.134  1.0
[/CIF]
.
The structure described by BaSr2I6 crystallizes in the monoclinic C2/c space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent I(1), two equivalent I(2), and four equivalent I(3) atoms. Sr(1) is bonded to two equivalent I(1), two equivalent I(2), and two equivalent I(3) atoms to form distorted edge-sharing SrI6 pentagonal pyramids. There are three inequivalent I sites. In the first I site, I(1) is bonded in a T-shaped geometry to one Ba(1) and two equivalent Sr(1) atoms. In the second I site, I(2) is bonded in a distorted T-shaped geometry to one Ba(1) and two equivalent Sr(1) atoms. In the third I site, I(3) is bonded to two equivalent Ba(1) and two equivalent Sr(1) atoms to form a mixture of distorted corner and edge-sharing IBa2Sr2 trigonal pyramids. is represented by the CIF file [CIF]
data_BaSr2I6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.974
_cell_length_b   8.974
_cell_length_c   11.921
_cell_angle_alpha   87.082
_cell_angle_beta   87.082
_cell_angle_gamma   119.301
_symmetry_Int_Tables_number   1
_cell_volume   832.996
_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
  Ba  Ba0  1  0.032  0.968  0.750  1.0
  Ba  Ba1  1  0.968  0.032  0.250  1.0
  Sr  Sr2  1  0.394  0.704  0.445  1.0
  Sr  Sr3  1  0.296  0.606  0.055  1.0
  Sr  Sr4  1  0.704  0.394  0.945  1.0
  Sr  Sr5  1  0.606  0.296  0.555  1.0
  I  I6  1  0.610  0.697  0.866  1.0
  I  I7  1  0.452  0.066  0.805  1.0
  I  I8  1  0.242  0.978  0.467  1.0
  I  I9  1  0.022  0.758  0.033  1.0
  I  I10  1  0.934  0.548  0.695  1.0
  I  I11  1  0.303  0.390  0.634  1.0
  I  I12  1  0.697  0.610  0.366  1.0
  I  I13  1  0.066  0.452  0.305  1.0
  I  I14  1  0.978  0.242  0.967  1.0
  I  I15  1  0.758  0.022  0.533  1.0
  I  I16  1  0.548  0.934  0.195  1.0
  I  I17  1  0.390  0.303  0.134  1.0
[/CIF]
.