The material structure described by BaCa2I6 is Hydrophilite-derived structured and crystallizes in the monoclinic C2/c space group. Ba(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form distorted BaI6 pentagonal pyramids that share corners with four equivalent Ca(1)I6 octahedra, edges with two equivalent Ca(1)I6 octahedra, and edges with two equivalent Ba(1)I6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 41-62°. Ca(1) is bonded to one I(1), two equivalent I(2), and three equivalent I(3) atoms to form CaI6 octahedra that share corners with six equivalent Ca(1)I6 octahedra, corners with two equivalent Ba(1)I6 pentagonal pyramids,  an edgeedge with one Ca(1)I6 octahedra, and  an edgeedge with one Ba(1)I6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 43-57°. There are three inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1) and one Ca(1) atom. In the second I site, I(2) is bonded in a distorted trigonal planar geometry to one Ba(1) and two equivalent Ca(1) atoms. In the third I site, I(3) is bonded in a distorted T-shaped geometry to three equivalent Ca(1) atoms. is represented by the CIF file [CIF]
data_BaCa2I6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.136
_cell_length_b   13.136
_cell_length_c   8.733
_cell_angle_alpha   86.263
_cell_angle_beta   86.263
_cell_angle_gamma   34.011
_symmetry_Int_Tables_number   1
_cell_volume   840.876
_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  0.749  0.251  0.250  1.0
  Ba  Ba1  1  0.251  0.749  0.750  1.0
  Ca  Ca2  1  0.057  0.597  0.129  1.0
  Ca  Ca3  1  0.597  0.057  0.629  1.0
  Ca  Ca4  1  0.403  0.943  0.371  1.0
  Ca  Ca5  1  0.943  0.403  0.871  1.0
  I  I6  1  0.357  0.506  0.081  1.0
  I  I7  1  0.506  0.357  0.581  1.0
  I  I8  1  0.909  0.866  0.382  1.0
  I  I9  1  0.866  0.909  0.882  1.0
  I  I10  1  0.325  0.241  0.357  1.0
  I  I11  1  0.241  0.325  0.857  1.0
  I  I12  1  0.759  0.675  0.143  1.0
  I  I13  1  0.675  0.759  0.643  1.0
  I  I14  1  0.134  0.091  0.118  1.0
  I  I15  1  0.091  0.134  0.618  1.0
  I  I16  1  0.494  0.643  0.419  1.0
  I  I17  1  0.643  0.494  0.919  1.0
[/CIF]
.
The material structure described by BaCa2I6 is Hydrophilite-derived structured and crystallizes in the monoclinic C2/c space group. Ba(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form distorted BaI6 pentagonal pyramids that share corners with four equivalent Ca(1)I6 octahedra, edges with two equivalent Ca(1)I6 octahedra, and edges with two equivalent Ba(1)I6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 41-62°. Ca(1) is bonded to one I(1), two equivalent I(2), and three equivalent I(3) atoms to form CaI6 octahedra that share corners with six equivalent Ca(1)I6 octahedra, corners with two equivalent Ba(1)I6 pentagonal pyramids,  an edgeedge with one Ca(1)I6 octahedra, and  an edgeedge with one Ba(1)I6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 43-57°. There are three inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1) and one Ca(1) atom. In the second I site, I(2) is bonded in a distorted trigonal planar geometry to one Ba(1) and two equivalent Ca(1) atoms. In the third I site, I(3) is bonded in a distorted T-shaped geometry to three equivalent Ca(1) atoms. is represented by the CIF file [CIF]
data_BaCa2I6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.136
_cell_length_b   13.136
_cell_length_c   8.733
_cell_angle_alpha   86.263
_cell_angle_beta   86.263
_cell_angle_gamma   34.011
_symmetry_Int_Tables_number   1
_cell_volume   840.876
_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  0.749  0.251  0.250  1.0
  Ba  Ba1  1  0.251  0.749  0.750  1.0
  Ca  Ca2  1  0.057  0.597  0.129  1.0
  Ca  Ca3  1  0.597  0.057  0.629  1.0
  Ca  Ca4  1  0.403  0.943  0.371  1.0
  Ca  Ca5  1  0.943  0.403  0.871  1.0
  I  I6  1  0.357  0.506  0.081  1.0
  I  I7  1  0.506  0.357  0.581  1.0
  I  I8  1  0.909  0.866  0.382  1.0
  I  I9  1  0.866  0.909  0.882  1.0
  I  I10  1  0.325  0.241  0.357  1.0
  I  I11  1  0.241  0.325  0.857  1.0
  I  I12  1  0.759  0.675  0.143  1.0
  I  I13  1  0.675  0.759  0.643  1.0
  I  I14  1  0.134  0.091  0.118  1.0
  I  I15  1  0.091  0.134  0.618  1.0
  I  I16  1  0.494  0.643  0.419  1.0
  I  I17  1  0.643  0.494  0.919  1.0
[/CIF]
.