The crystal structure described by Ba2SrI6 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(3), and four equivalent I(2) atoms. Sr(1) is bonded in a 8-coordinate geometry to two equivalent I(1), two equivalent I(2), and four equivalent I(3) atoms. There are three inequivalent I sites. In the first I site, I(1) is bonded in a T-shaped geometry to two equivalent Ba(1) and one Sr(1) atom. In the second I site, I(2) is bonded to four equivalent Ba(1) and one Sr(1) atom to form distorted IBa4Sr square pyramids that share corners with four equivalent I(2)Ba4Sr square pyramids, corners with five equivalent I(3)Ba2Sr2 trigonal pyramids, edges with three equivalent I(2)Ba4Sr square pyramids, edges with two equivalent I(3)Ba2Sr2 trigonal pyramids,  a faceface with one I(2)Ba4Sr square pyramid, and  a faceface with one I(3)Ba2Sr2 trigonal pyramid. In the third I site, I(3) is bonded to two equivalent Ba(1) and two equivalent Sr(1) atoms to form distorted IBa2Sr2 trigonal pyramids that share corners with five equivalent I(2)Ba4Sr square pyramids, corners with four equivalent I(3)Ba2Sr2 trigonal pyramids, edges with two equivalent I(2)Ba4Sr square pyramids, edges with two equivalent I(3)Ba2Sr2 trigonal pyramids, and  a faceface with one I(2)Ba4Sr square pyramid. is represented by the CIF file [CIF]
data_Ba2SrI6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.330
_cell_length_b   9.330
_cell_length_c   10.453
_cell_angle_alpha   88.849
_cell_angle_beta   88.849
_cell_angle_gamma   119.998
_symmetry_Int_Tables_number   1
_cell_volume   787.347
_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  0.282  0.611  0.492  1.0
  Ba  Ba1  1  0.389  0.718  0.008  1.0
  Ba  Ba2  1  0.611  0.282  0.992  1.0
  Ba  Ba3  1  0.718  0.389  0.508  1.0
  Sr  Sr4  1  0.048  0.952  0.250  1.0
  Sr  Sr5  1  0.952  0.048  0.750  1.0
  I  I6  1  0.308  0.350  0.148  1.0
  I  I7  1  0.986  0.557  0.212  1.0
  I  I8  1  0.051  0.807  0.552  1.0
  I  I9  1  0.193  0.949  0.948  1.0
  I  I10  1  0.443  0.014  0.288  1.0
  I  I11  1  0.650  0.692  0.352  1.0
  I  I12  1  0.350  0.308  0.648  1.0
  I  I13  1  0.557  0.986  0.712  1.0
  I  I14  1  0.807  0.051  0.052  1.0
  I  I15  1  0.949  0.193  0.448  1.0
  I  I16  1  0.014  0.443  0.788  1.0
  I  I17  1  0.692  0.650  0.852  1.0
[/CIF]
.
The crystal structure described by Ba2SrI6 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(3), and four equivalent I(2) atoms. Sr(1) is bonded in a 8-coordinate geometry to two equivalent I(1), two equivalent I(2), and four equivalent I(3) atoms. There are three inequivalent I sites. In the first I site, I(1) is bonded in a T-shaped geometry to two equivalent Ba(1) and one Sr(1) atom. In the second I site, I(2) is bonded to four equivalent Ba(1) and one Sr(1) atom to form distorted IBa4Sr square pyramids that share corners with four equivalent I(2)Ba4Sr square pyramids, corners with five equivalent I(3)Ba2Sr2 trigonal pyramids, edges with three equivalent I(2)Ba4Sr square pyramids, edges with two equivalent I(3)Ba2Sr2 trigonal pyramids,  a faceface with one I(2)Ba4Sr square pyramid, and  a faceface with one I(3)Ba2Sr2 trigonal pyramid. In the third I site, I(3) is bonded to two equivalent Ba(1) and two equivalent Sr(1) atoms to form distorted IBa2Sr2 trigonal pyramids that share corners with five equivalent I(2)Ba4Sr square pyramids, corners with four equivalent I(3)Ba2Sr2 trigonal pyramids, edges with two equivalent I(2)Ba4Sr square pyramids, edges with two equivalent I(3)Ba2Sr2 trigonal pyramids, and  a faceface with one I(2)Ba4Sr square pyramid. is represented by the CIF file [CIF]
data_Ba2SrI6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.330
_cell_length_b   9.330
_cell_length_c   10.453
_cell_angle_alpha   88.849
_cell_angle_beta   88.849
_cell_angle_gamma   119.998
_symmetry_Int_Tables_number   1
_cell_volume   787.347
_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  0.282  0.611  0.492  1.0
  Ba  Ba1  1  0.389  0.718  0.008  1.0
  Ba  Ba2  1  0.611  0.282  0.992  1.0
  Ba  Ba3  1  0.718  0.389  0.508  1.0
  Sr  Sr4  1  0.048  0.952  0.250  1.0
  Sr  Sr5  1  0.952  0.048  0.750  1.0
  I  I6  1  0.308  0.350  0.148  1.0
  I  I7  1  0.986  0.557  0.212  1.0
  I  I8  1  0.051  0.807  0.552  1.0
  I  I9  1  0.193  0.949  0.948  1.0
  I  I10  1  0.443  0.014  0.288  1.0
  I  I11  1  0.650  0.692  0.352  1.0
  I  I12  1  0.350  0.308  0.648  1.0
  I  I13  1  0.557  0.986  0.712  1.0
  I  I14  1  0.807  0.051  0.052  1.0
  I  I15  1  0.949  0.193  0.448  1.0
  I  I16  1  0.014  0.443  0.788  1.0
  I  I17  1  0.692  0.650  0.852  1.0
[/CIF]
.