The crystal structure described by CaIr3Si7 crystallizes in the trigonal R-3c space group. Ca(1) is bonded in a 18-coordinate geometry to six equivalent Ir(1) and twelve equivalent Si(1) atoms. Ir(1) is bonded in a 9-coordinate geometry to two equivalent Ca(1), one Si(2), and six equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a trigonal planar geometry to three equivalent Ir(1) atoms. In the second Si site, Si(1) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and three equivalent Ir(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaSi7Ir3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.030
_cell_length_b   8.030
_cell_length_c   8.030
_cell_angle_alpha   56.799
_cell_angle_beta   56.799
_cell_angle_gamma   56.799
_symmetry_Int_Tables_number   1
_cell_volume   339.103
_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  0.500  0.500  0.500  1.0
  Ca  Ca1  1  0.000  0.000  0.000  1.0
  Si  Si2  1  0.067  0.850  0.673  1.0
  Si  Si3  1  0.673  0.067  0.850  1.0
  Si  Si4  1  0.850  0.673  0.067  1.0
  Si  Si5  1  0.173  0.350  0.567  1.0
  Si  Si6  1  0.567  0.173  0.350  1.0
  Si  Si7  1  0.350  0.567  0.173  1.0
  Si  Si8  1  0.933  0.150  0.327  1.0
  Si  Si9  1  0.327  0.933  0.150  1.0
  Si  Si10  1  0.150  0.327  0.933  1.0
  Si  Si11  1  0.827  0.650  0.433  1.0
  Si  Si12  1  0.433  0.827  0.650  1.0
  Si  Si13  1  0.650  0.433  0.827  1.0
  Si  Si14  1  0.750  0.750  0.750  1.0
  Si  Si15  1  0.250  0.250  0.250  1.0
  Ir  Ir16  1  0.070  0.750  0.430  1.0
  Ir  Ir17  1  0.430  0.070  0.750  1.0
  Ir  Ir18  1  0.750  0.430  0.070  1.0
  Ir  Ir19  1  0.930  0.250  0.570  1.0
  Ir  Ir20  1  0.570  0.930  0.250  1.0
  Ir  Ir21  1  0.250  0.570  0.930  1.0
[/CIF]
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The crystal structure described by CaIr3Si7 crystallizes in the trigonal R-3c space group. Ca(1) is bonded in a 18-coordinate geometry to six equivalent Ir(1) and twelve equivalent Si(1) atoms. Ir(1) is bonded in a 9-coordinate geometry to two equivalent Ca(1), one Si(2), and six equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(2) is bonded in a trigonal planar geometry to three equivalent Ir(1) atoms. In the second Si site, Si(1) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and three equivalent Ir(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaSi7Ir3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.030
_cell_length_b   8.030
_cell_length_c   8.030
_cell_angle_alpha   56.799
_cell_angle_beta   56.799
_cell_angle_gamma   56.799
_symmetry_Int_Tables_number   1
_cell_volume   339.103
_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  0.500  0.500  0.500  1.0
  Ca  Ca1  1  0.000  0.000  0.000  1.0
  Si  Si2  1  0.067  0.850  0.673  1.0
  Si  Si3  1  0.673  0.067  0.850  1.0
  Si  Si4  1  0.850  0.673  0.067  1.0
  Si  Si5  1  0.173  0.350  0.567  1.0
  Si  Si6  1  0.567  0.173  0.350  1.0
  Si  Si7  1  0.350  0.567  0.173  1.0
  Si  Si8  1  0.933  0.150  0.327  1.0
  Si  Si9  1  0.327  0.933  0.150  1.0
  Si  Si10  1  0.150  0.327  0.933  1.0
  Si  Si11  1  0.827  0.650  0.433  1.0
  Si  Si12  1  0.433  0.827  0.650  1.0
  Si  Si13  1  0.650  0.433  0.827  1.0
  Si  Si14  1  0.750  0.750  0.750  1.0
  Si  Si15  1  0.250  0.250  0.250  1.0
  Ir  Ir16  1  0.070  0.750  0.430  1.0
  Ir  Ir17  1  0.430  0.070  0.750  1.0
  Ir  Ir18  1  0.750  0.430  0.070  1.0
  Ir  Ir19  1  0.930  0.250  0.570  1.0
  Ir  Ir20  1  0.570  0.930  0.250  1.0
  Ir  Ir21  1  0.250  0.570  0.930  1.0
[/CIF]
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