The structure described by CaSi3 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 12-coordinate geometry to four equivalent Si(1) and eight equivalent Si(2) atoms. In the second Ca site, Ca(2) is bonded in a 12-coordinate geometry to four equivalent Si(1) and eight equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Si(1), and four equivalent Si(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), two equivalent Si(1), and three equivalent Si(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaSi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.649
_cell_length_b   7.649
_cell_length_c   7.649
_cell_angle_alpha   123.341
_cell_angle_beta   123.341
_cell_angle_gamma   84.304
_symmetry_Int_Tables_number   1
_cell_volume   298.882
_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
  Ca  Ca0  1  0.827  0.827  0.000  1.0
  Ca  Ca1  1  0.173  0.173  0.000  1.0
  Ca  Ca2  1  0.250  0.750  0.500  1.0
  Ca  Ca3  1  0.750  0.250  0.500  1.0
  Si  Si4  1  0.335  0.000  0.335  1.0
  Si  Si5  1  0.665  0.000  0.665  1.0
  Si  Si6  1  0.000  0.665  0.665  1.0
  Si  Si7  1  0.000  0.335  0.335  1.0
  Si  Si8  1  0.210  0.210  0.629  1.0
  Si  Si9  1  0.581  0.581  0.371  1.0
  Si  Si10  1  0.210  0.581  0.000  1.0
  Si  Si11  1  0.581  0.210  0.000  1.0
  Si  Si12  1  0.790  0.790  0.371  1.0
  Si  Si13  1  0.419  0.419  0.629  1.0
  Si  Si14  1  0.790  0.419  0.000  1.0
  Si  Si15  1  0.419  0.790  0.000  1.0
[/CIF]
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The structure described by CaSi3 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 12-coordinate geometry to four equivalent Si(1) and eight equivalent Si(2) atoms. In the second Ca site, Ca(2) is bonded in a 12-coordinate geometry to four equivalent Si(1) and eight equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Si(1), and four equivalent Si(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), two equivalent Si(1), and three equivalent Si(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaSi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.649
_cell_length_b   7.649
_cell_length_c   7.649
_cell_angle_alpha   123.341
_cell_angle_beta   123.341
_cell_angle_gamma   84.304
_symmetry_Int_Tables_number   1
_cell_volume   298.882
_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
  Ca  Ca0  1  0.827  0.827  0.000  1.0
  Ca  Ca1  1  0.173  0.173  0.000  1.0
  Ca  Ca2  1  0.250  0.750  0.500  1.0
  Ca  Ca3  1  0.750  0.250  0.500  1.0
  Si  Si4  1  0.335  0.000  0.335  1.0
  Si  Si5  1  0.665  0.000  0.665  1.0
  Si  Si6  1  0.000  0.665  0.665  1.0
  Si  Si7  1  0.000  0.335  0.335  1.0
  Si  Si8  1  0.210  0.210  0.629  1.0
  Si  Si9  1  0.581  0.581  0.371  1.0
  Si  Si10  1  0.210  0.581  0.000  1.0
  Si  Si11  1  0.581  0.210  0.000  1.0
  Si  Si12  1  0.790  0.790  0.371  1.0
  Si  Si13  1  0.419  0.419  0.629  1.0
  Si  Si14  1  0.790  0.419  0.000  1.0
  Si  Si15  1  0.419  0.790  0.000  1.0
[/CIF]
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