The compound described by SrCa3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Sr(1) is bonded to four equivalent Ca(2) and eight equivalent Ca(1) atoms to form SrCa12 cuboctahedra that share corners with four equivalent Sr(1)Ca12 cuboctahedra, corners with eight equivalent Ca(2)Sr4Ca8 cuboctahedra, edges with eight equivalent Sr(1)Ca12 cuboctahedra, edges with sixteen equivalent Ca(1)Sr4Ca8 cuboctahedra, faces with four equivalent Sr(1)Ca12 cuboctahedra, faces with six equivalent Ca(2)Sr4Ca8 cuboctahedra, and faces with eight equivalent Ca(1)Sr4Ca8 cuboctahedra. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to four equivalent Sr(1), four equivalent Ca(1), and four equivalent Ca(2) atoms to form CaSr4Ca8 cuboctahedra that share corners with twelve equivalent Ca(1)Sr4Ca8 cuboctahedra, edges with eight equivalent Sr(1)Ca12 cuboctahedra, edges with eight equivalent Ca(1)Sr4Ca8 cuboctahedra, edges with eight equivalent Ca(2)Sr4Ca8 cuboctahedra, faces with four equivalent Sr(1)Ca12 cuboctahedra, faces with four equivalent Ca(2)Sr4Ca8 cuboctahedra, and faces with ten equivalent Ca(1)Sr4Ca8 cuboctahedra. In the second Ca site, Ca(2) is bonded to four equivalent Sr(1) and eight equivalent Ca(1) atoms to form CaSr4Ca8 cuboctahedra that share corners with four equivalent Ca(2)Sr4Ca8 cuboctahedra, corners with eight equivalent Sr(1)Ca12 cuboctahedra, edges with eight equivalent Ca(2)Sr4Ca8 cuboctahedra, edges with sixteen equivalent Ca(1)Sr4Ca8 cuboctahedra, faces with four equivalent Ca(2)Sr4Ca8 cuboctahedra, faces with six equivalent Sr(1)Ca12 cuboctahedra, and faces with eight equivalent Ca(1)Sr4Ca8 cuboctahedra. is represented by the CIF file [CIF]
data_SrCa3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.965
_cell_length_b   6.965
_cell_length_c   6.965
_cell_angle_alpha   131.402
_cell_angle_beta   131.402
_cell_angle_gamma   71.176
_symmetry_Int_Tables_number   1
_cell_volume   186.098
_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  0.000  0.000  0.000  1.0
  Ca  Ca1  1  0.750  0.250  0.500  1.0
  Ca  Ca2  1  0.250  0.750  0.500  1.0
  Ca  Ca3  1  0.500  0.500  0.000  1.0
[/CIF]
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The compound described by SrCa3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Sr(1) is bonded to four equivalent Ca(2) and eight equivalent Ca(1) atoms to form SrCa12 cuboctahedra that share corners with four equivalent Sr(1)Ca12 cuboctahedra, corners with eight equivalent Ca(2)Sr4Ca8 cuboctahedra, edges with eight equivalent Sr(1)Ca12 cuboctahedra, edges with sixteen equivalent Ca(1)Sr4Ca8 cuboctahedra, faces with four equivalent Sr(1)Ca12 cuboctahedra, faces with six equivalent Ca(2)Sr4Ca8 cuboctahedra, and faces with eight equivalent Ca(1)Sr4Ca8 cuboctahedra. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to four equivalent Sr(1), four equivalent Ca(1), and four equivalent Ca(2) atoms to form CaSr4Ca8 cuboctahedra that share corners with twelve equivalent Ca(1)Sr4Ca8 cuboctahedra, edges with eight equivalent Sr(1)Ca12 cuboctahedra, edges with eight equivalent Ca(1)Sr4Ca8 cuboctahedra, edges with eight equivalent Ca(2)Sr4Ca8 cuboctahedra, faces with four equivalent Sr(1)Ca12 cuboctahedra, faces with four equivalent Ca(2)Sr4Ca8 cuboctahedra, and faces with ten equivalent Ca(1)Sr4Ca8 cuboctahedra. In the second Ca site, Ca(2) is bonded to four equivalent Sr(1) and eight equivalent Ca(1) atoms to form CaSr4Ca8 cuboctahedra that share corners with four equivalent Ca(2)Sr4Ca8 cuboctahedra, corners with eight equivalent Sr(1)Ca12 cuboctahedra, edges with eight equivalent Ca(2)Sr4Ca8 cuboctahedra, edges with sixteen equivalent Ca(1)Sr4Ca8 cuboctahedra, faces with four equivalent Ca(2)Sr4Ca8 cuboctahedra, faces with six equivalent Sr(1)Ca12 cuboctahedra, and faces with eight equivalent Ca(1)Sr4Ca8 cuboctahedra. is represented by the CIF file [CIF]
data_SrCa3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.965
_cell_length_b   6.965
_cell_length_c   6.965
_cell_angle_alpha   131.402
_cell_angle_beta   131.402
_cell_angle_gamma   71.176
_symmetry_Int_Tables_number   1
_cell_volume   186.098
_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  0.000  0.000  0.000  1.0
  Ca  Ca1  1  0.750  0.250  0.500  1.0
  Ca  Ca2  1  0.250  0.750  0.500  1.0
  Ca  Ca3  1  0.500  0.500  0.000  1.0
[/CIF]
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