The crystal structure described by Ca2Sb2O7 crystallizes in the cubic Fd-3m space group. Ca(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(2) atoms. Sb(1) is bonded in a body-centered cubic geometry to two equivalent O(1) and six equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sb(1) atoms to form OSb4 tetrahedra that share corners with four equivalent O(1)Sb4 tetrahedra, corners with twelve equivalent O(2)Ca2Sb2 tetrahedra, and edges with six equivalent O(2)Ca2Sb2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Sb(1) atoms to form OCa2Sb2 tetrahedra that share corners with two equivalent O(1)Sb4 tetrahedra, corners with twelve equivalent O(2)Ca2Sb2 tetrahedra,  an edgeedge with one O(1)Sb4 tetrahedra, and edges with four equivalent O(2)Ca2Sb2 tetrahedra. is represented by the CIF file [CIF]
data_Ca2Sb2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.346
_cell_length_b   7.346
_cell_length_c   7.346
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   280.297
_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  0.125  0.125  0.125  1.0
  Ca  Ca1  1  0.625  0.125  0.125  1.0
  Ca  Ca2  1  0.125  0.625  0.125  1.0
  Ca  Ca3  1  0.125  0.125  0.625  1.0
  Sb  Sb4  1  0.625  0.625  0.625  1.0
  Sb  Sb5  1  0.125  0.625  0.625  1.0
  Sb  Sb6  1  0.625  0.125  0.625  1.0
  Sb  Sb7  1  0.625  0.625  0.125  1.0
  O  O8  1  0.750  0.750  0.750  1.0
  O  O9  1  0.500  0.500  0.500  1.0
  O  O10  1  0.265  0.735  0.265  1.0
  O  O11  1  0.515  0.985  0.515  1.0
  O  O12  1  0.265  0.265  0.735  1.0
  O  O13  1  0.735  0.265  0.265  1.0
  O  O14  1  0.265  0.735  0.735  1.0
  O  O15  1  0.735  0.735  0.265  1.0
  O  O16  1  0.735  0.265  0.735  1.0
  O  O17  1  0.985  0.515  0.515  1.0
  O  O18  1  0.515  0.985  0.985  1.0
  O  O19  1  0.985  0.515  0.985  1.0
  O  O20  1  0.515  0.515  0.985  1.0
  O  O21  1  0.985  0.985  0.515  1.0
[/CIF]
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The crystal structure described by Ca2Sb2O7 crystallizes in the cubic Fd-3m space group. Ca(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(2) atoms. Sb(1) is bonded in a body-centered cubic geometry to two equivalent O(1) and six equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sb(1) atoms to form OSb4 tetrahedra that share corners with four equivalent O(1)Sb4 tetrahedra, corners with twelve equivalent O(2)Ca2Sb2 tetrahedra, and edges with six equivalent O(2)Ca2Sb2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Sb(1) atoms to form OCa2Sb2 tetrahedra that share corners with two equivalent O(1)Sb4 tetrahedra, corners with twelve equivalent O(2)Ca2Sb2 tetrahedra,  an edgeedge with one O(1)Sb4 tetrahedra, and edges with four equivalent O(2)Ca2Sb2 tetrahedra. is represented by the CIF file [CIF]
data_Ca2Sb2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.346
_cell_length_b   7.346
_cell_length_c   7.346
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   280.297
_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  0.125  0.125  0.125  1.0
  Ca  Ca1  1  0.625  0.125  0.125  1.0
  Ca  Ca2  1  0.125  0.625  0.125  1.0
  Ca  Ca3  1  0.125  0.125  0.625  1.0
  Sb  Sb4  1  0.625  0.625  0.625  1.0
  Sb  Sb5  1  0.125  0.625  0.625  1.0
  Sb  Sb6  1  0.625  0.125  0.625  1.0
  Sb  Sb7  1  0.625  0.625  0.125  1.0
  O  O8  1  0.750  0.750  0.750  1.0
  O  O9  1  0.500  0.500  0.500  1.0
  O  O10  1  0.265  0.735  0.265  1.0
  O  O11  1  0.515  0.985  0.515  1.0
  O  O12  1  0.265  0.265  0.735  1.0
  O  O13  1  0.735  0.265  0.265  1.0
  O  O14  1  0.265  0.735  0.735  1.0
  O  O15  1  0.735  0.735  0.265  1.0
  O  O16  1  0.735  0.265  0.735  1.0
  O  O17  1  0.985  0.515  0.515  1.0
  O  O18  1  0.515  0.985  0.985  1.0
  O  O19  1  0.985  0.515  0.985  1.0
  O  O20  1  0.515  0.515  0.985  1.0
  O  O21  1  0.985  0.985  0.515  1.0
[/CIF]
.