The compound described by CaSi2 is hexagonal omega structure-like structured and crystallizes in the tetragonal I4_1/amd space group. Ca(1) is bonded to twelve Si(1,1,1) atoms to form a mixture of edge and face-sharing CaSi12 cuboctahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three Si(1,1) atoms. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three Si(1,1) atoms. In the third Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three Si(1,1) atoms. is represented by the CIF card [CIF]
data_CaSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.257
_cell_length_b   4.257
_cell_length_c   7.401
_cell_angle_alpha   106.712
_cell_angle_beta   106.712
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   122.516
_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
  Ca  Ca0  1  0.625  0.875  0.750  1.0
  Ca  Ca1  1  0.375  0.125  0.250  1.0
  Si  Si2  1  0.210  0.460  0.919  1.0
  Si  Si3  1  0.960  0.710  0.419  1.0
  Si  Si4  1  0.040  0.290  0.581  1.0
  Si  Si5  1  0.790  0.540  0.081  1.0
[/CIF]
.
The compound described by CaSi2 is hexagonal omega structure-like structured and crystallizes in the tetragonal I4_1/amd space group. Ca(1) is bonded to twelve Si(1,1,1) atoms to form a mixture of edge and face-sharing CaSi12 cuboctahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three Si(1,1) atoms. In the second Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three Si(1,1) atoms. In the third Si site, Si(1) is bonded in a 9-coordinate geometry to six equivalent Ca(1) and three Si(1,1) atoms. is represented by the CIF card [CIF]
data_CaSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.257
_cell_length_b   4.257
_cell_length_c   7.401
_cell_angle_alpha   106.712
_cell_angle_beta   106.712
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   122.516
_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
  Ca  Ca0  1  0.625  0.875  0.750  1.0
  Ca  Ca1  1  0.375  0.125  0.250  1.0
  Si  Si2  1  0.210  0.460  0.919  1.0
  Si  Si3  1  0.960  0.710  0.419  1.0
  Si  Si4  1  0.040  0.290  0.581  1.0
  Si  Si5  1  0.790  0.540  0.081  1.0
[/CIF]
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