The material described by CaSi2 is alpha boron-derived structured and crystallizes in the trigonal R-3m space group. Ca(1) is bonded in a 7-coordinate geometry to three equivalent Si(1) and four equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a 7-coordinate geometry to four equivalent Ca(1) and three equivalent Si(2) atoms. In the second Si site, Si(1) is bonded in a 6-coordinate geometry to three equivalent Ca(1) and three equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_CaSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.360
_cell_length_b   10.360
_cell_length_c   10.360
_cell_angle_alpha   21.528
_cell_angle_beta   21.528
_cell_angle_gamma   21.528
_symmetry_Int_Tables_number   1
_cell_volume   131.181
_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  0.920  0.920  0.920  1.0
  Ca  Ca1  1  0.080  0.080  0.080  1.0
  Si  Si2  1  0.653  0.653  0.653  1.0
  Si  Si3  1  0.347  0.347  0.347  1.0
  Si  Si4  1  0.182  0.182  0.182  1.0
  Si  Si5  1  0.818  0.818  0.818  1.0
[/CIF]
.
The material described by CaSi2 is alpha boron-derived structured and crystallizes in the trigonal R-3m space group. Ca(1) is bonded in a 7-coordinate geometry to three equivalent Si(1) and four equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a 7-coordinate geometry to four equivalent Ca(1) and three equivalent Si(2) atoms. In the second Si site, Si(1) is bonded in a 6-coordinate geometry to three equivalent Ca(1) and three equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_CaSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.360
_cell_length_b   10.360
_cell_length_c   10.360
_cell_angle_alpha   21.528
_cell_angle_beta   21.528
_cell_angle_gamma   21.528
_symmetry_Int_Tables_number   1
_cell_volume   131.181
_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  0.920  0.920  0.920  1.0
  Ca  Ca1  1  0.080  0.080  0.080  1.0
  Si  Si2  1  0.653  0.653  0.653  1.0
  Si  Si3  1  0.347  0.347  0.347  1.0
  Si  Si4  1  0.182  0.182  0.182  1.0
  Si  Si5  1  0.818  0.818  0.818  1.0
[/CIF]
.