The material described by Sr3CaSi8 crystallizes in the trigonal R32 space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent Si(1) and six equivalent Si(2) atoms. Ca(1) is bonded in a distorted body-centered cubic geometry to two equivalent Si(1) and six equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to three equivalent Sr(1), one Ca(1), and three equivalent Si(2) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to three equivalent Sr(1), one Ca(1), one Si(1), and two equivalent Si(2) atoms. is represented by the CIF file [CIF]
data_Sr3CaSi8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.514
_cell_length_b   6.514
_cell_length_c   6.514
_cell_angle_alpha   89.654
_cell_angle_beta   89.654
_cell_angle_gamma   89.654
_symmetry_Int_Tables_number   1
_cell_volume   276.375
_cell_formula_units_Z   1
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
  Sr  Sr0  1  0.251  0.749  0.000  1.0
  Sr  Sr1  1  0.000  0.251  0.749  1.0
  Sr  Sr2  1  0.749  0.000  0.251  1.0
  Ca  Ca3  1  0.500  0.500  0.500  1.0
  Si  Si4  1  0.205  0.205  0.205  1.0
  Si  Si5  1  0.547  0.051  0.700  1.0
  Si  Si6  1  0.700  0.547  0.051  1.0
  Si  Si7  1  0.051  0.700  0.547  1.0
  Si  Si8  1  0.795  0.795  0.795  1.0
  Si  Si9  1  0.300  0.949  0.453  1.0
  Si  Si10  1  0.949  0.453  0.300  1.0
  Si  Si11  1  0.453  0.300  0.949  1.0
[/CIF]
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The material described by Sr3CaSi8 crystallizes in the trigonal R32 space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent Si(1) and six equivalent Si(2) atoms. Ca(1) is bonded in a distorted body-centered cubic geometry to two equivalent Si(1) and six equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to three equivalent Sr(1), one Ca(1), and three equivalent Si(2) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to three equivalent Sr(1), one Ca(1), one Si(1), and two equivalent Si(2) atoms. is represented by the CIF file [CIF]
data_Sr3CaSi8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.514
_cell_length_b   6.514
_cell_length_c   6.514
_cell_angle_alpha   89.654
_cell_angle_beta   89.654
_cell_angle_gamma   89.654
_symmetry_Int_Tables_number   1
_cell_volume   276.375
_cell_formula_units_Z   1
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
  Sr  Sr0  1  0.251  0.749  0.000  1.0
  Sr  Sr1  1  0.000  0.251  0.749  1.0
  Sr  Sr2  1  0.749  0.000  0.251  1.0
  Ca  Ca3  1  0.500  0.500  0.500  1.0
  Si  Si4  1  0.205  0.205  0.205  1.0
  Si  Si5  1  0.547  0.051  0.700  1.0
  Si  Si6  1  0.700  0.547  0.051  1.0
  Si  Si7  1  0.051  0.700  0.547  1.0
  Si  Si8  1  0.795  0.795  0.795  1.0
  Si  Si9  1  0.300  0.949  0.453  1.0
  Si  Si10  1  0.949  0.453  0.300  1.0
  Si  Si11  1  0.453  0.300  0.949  1.0
[/CIF]
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