The material structure described by BaCaI4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one I(3), one I(4), two equivalent I(2), and two equivalent I(5) atoms to form distorted BaI6 octahedra that share corners with two equivalent Ca(1)I6 octahedra, corners with two equivalent Ca(2)I6 octahedra,  an edgeedge with one Ca(1)I6 octahedra, edges with two equivalent Ba(2)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 11-24°. In the second Ba site, Ba(2) is bonded to two equivalent I(1), two equivalent I(4), and two equivalent I(5) atoms to form distorted BaI6 octahedra that share corners with two equivalent Ca(1)I6 octahedra, corners with two equivalent Ca(2)I6 octahedra,  an edgeedge with one Ba(2)I6 octahedra, edges with two equivalent Ba(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-21°. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one I(3), one I(4), two equivalent I(1), and two equivalent I(5) atoms to form CaI6 octahedra that share corners with two equivalent Ba(1)I6 octahedra, corners with two equivalent Ba(2)I6 octahedra,  an edgeedge with one Ba(1)I6 octahedra, edges with two equivalent Ba(2)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-24°. In the second Ca site, Ca(2) is bonded to two equivalent I(2), two equivalent I(3), and two equivalent I(5) atoms to form CaI6 octahedra that share corners with two equivalent Ba(1)I6 octahedra, corners with two equivalent Ba(2)I6 octahedra,  an edgeedge with one Ca(2)I6 octahedra, edges with two equivalent Ba(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 11-21°. There are five inequivalent I sites. In the first I site, I(1) is bonded in a linear geometry to one Ba(2) and one Ca(1) atom. In the second I site, I(2) is bonded in a linear geometry to one Ba(1) and one Ca(2) atom. In the third I site, I(3) is bonded in a distorted see-saw-like geometry to one Ba(1), one Ca(1), and two equivalent Ca(2) atoms. In the fourth I site, I(4) is bonded in a see-saw-like geometry to one Ba(1), two equivalent Ba(2), and one Ca(1) atom. In the fifth I site, I(5) is bonded in a distorted see-saw-like geometry to one Ba(1), one Ba(2), one Ca(1), and one Ca(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_BaCaI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.715
_cell_length_b   10.715
_cell_length_c   13.317
_cell_angle_alpha   71.221
_cell_angle_beta   71.221
_cell_angle_gamma   83.795
_symmetry_Int_Tables_number   1
_cell_volume   1370.635
_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
  Ba  Ba0  1  0.700  0.700  0.145  1.0
  Ba  Ba1  1  0.701  0.299  0.500  1.0
  Ba  Ba2  1  0.299  0.701  0.500  1.0
  Ba  Ba3  1  0.300  0.300  0.855  1.0
  Ca  Ca4  1  0.683  0.683  0.659  1.0
  Ca  Ca5  1  0.682  0.318  0.000  1.0
  Ca  Ca6  1  0.318  0.682  0.000  1.0
  Ca  Ca7  1  0.317  0.317  0.341  1.0
  I  I8  1  0.664  0.976  0.588  1.0
  I  I9  1  0.976  0.664  0.588  1.0
  I  I10  1  0.338  0.976  0.924  1.0
  I  I11  1  0.976  0.338  0.924  1.0
  I  I12  1  0.643  0.643  0.919  1.0
  I  I13  1  0.653  0.653  0.431  1.0
  I  I14  1  0.359  0.654  0.756  1.0
  I  I15  1  0.654  0.359  0.756  1.0
  I  I16  1  0.641  0.346  0.244  1.0
  I  I17  1  0.346  0.641  0.244  1.0
  I  I18  1  0.347  0.347  0.569  1.0
  I  I19  1  0.357  0.357  0.081  1.0
  I  I20  1  0.662  0.024  0.076  1.0
  I  I21  1  0.024  0.662  0.076  1.0
  I  I22  1  0.336  0.024  0.412  1.0
  I  I23  1  0.024  0.336  0.412  1.0
[/CIF]
.
The material structure described by BaCaI4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one I(3), one I(4), two equivalent I(2), and two equivalent I(5) atoms to form distorted BaI6 octahedra that share corners with two equivalent Ca(1)I6 octahedra, corners with two equivalent Ca(2)I6 octahedra,  an edgeedge with one Ca(1)I6 octahedra, edges with two equivalent Ba(2)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 11-24°. In the second Ba site, Ba(2) is bonded to two equivalent I(1), two equivalent I(4), and two equivalent I(5) atoms to form distorted BaI6 octahedra that share corners with two equivalent Ca(1)I6 octahedra, corners with two equivalent Ca(2)I6 octahedra,  an edgeedge with one Ba(2)I6 octahedra, edges with two equivalent Ba(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-21°. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one I(3), one I(4), two equivalent I(1), and two equivalent I(5) atoms to form CaI6 octahedra that share corners with two equivalent Ba(1)I6 octahedra, corners with two equivalent Ba(2)I6 octahedra,  an edgeedge with one Ba(1)I6 octahedra, edges with two equivalent Ba(2)I6 octahedra, and edges with two equivalent Ca(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 10-24°. In the second Ca site, Ca(2) is bonded to two equivalent I(2), two equivalent I(3), and two equivalent I(5) atoms to form CaI6 octahedra that share corners with two equivalent Ba(1)I6 octahedra, corners with two equivalent Ba(2)I6 octahedra,  an edgeedge with one Ca(2)I6 octahedra, edges with two equivalent Ba(1)I6 octahedra, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 11-21°. There are five inequivalent I sites. In the first I site, I(1) is bonded in a linear geometry to one Ba(2) and one Ca(1) atom. In the second I site, I(2) is bonded in a linear geometry to one Ba(1) and one Ca(2) atom. In the third I site, I(3) is bonded in a distorted see-saw-like geometry to one Ba(1), one Ca(1), and two equivalent Ca(2) atoms. In the fourth I site, I(4) is bonded in a see-saw-like geometry to one Ba(1), two equivalent Ba(2), and one Ca(1) atom. In the fifth I site, I(5) is bonded in a distorted see-saw-like geometry to one Ba(1), one Ba(2), one Ca(1), and one Ca(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_BaCaI4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.715
_cell_length_b   10.715
_cell_length_c   13.317
_cell_angle_alpha   71.221
_cell_angle_beta   71.221
_cell_angle_gamma   83.795
_symmetry_Int_Tables_number   1
_cell_volume   1370.635
_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
  Ba  Ba0  1  0.700  0.700  0.145  1.0
  Ba  Ba1  1  0.701  0.299  0.500  1.0
  Ba  Ba2  1  0.299  0.701  0.500  1.0
  Ba  Ba3  1  0.300  0.300  0.855  1.0
  Ca  Ca4  1  0.683  0.683  0.659  1.0
  Ca  Ca5  1  0.682  0.318  0.000  1.0
  Ca  Ca6  1  0.318  0.682  0.000  1.0
  Ca  Ca7  1  0.317  0.317  0.341  1.0
  I  I8  1  0.664  0.976  0.588  1.0
  I  I9  1  0.976  0.664  0.588  1.0
  I  I10  1  0.338  0.976  0.924  1.0
  I  I11  1  0.976  0.338  0.924  1.0
  I  I12  1  0.643  0.643  0.919  1.0
  I  I13  1  0.653  0.653  0.431  1.0
  I  I14  1  0.359  0.654  0.756  1.0
  I  I15  1  0.654  0.359  0.756  1.0
  I  I16  1  0.641  0.346  0.244  1.0
  I  I17  1  0.346  0.641  0.244  1.0
  I  I18  1  0.347  0.347  0.569  1.0
  I  I19  1  0.357  0.357  0.081  1.0
  I  I20  1  0.662  0.024  0.076  1.0
  I  I21  1  0.024  0.662  0.076  1.0
  I  I22  1  0.336  0.024  0.412  1.0
  I  I23  1  0.024  0.336  0.412  1.0
[/CIF]
.