The structure described by Ca2Bi2O5 crystallizes in the orthorhombic Pbam space group. Ca(1) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. Bi(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted corner-sharing BiO5 square pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ca(1) and two equivalent Bi(1) atoms to form distorted OCa4Bi2 octahedra that share corners with eight equivalent O(2)Ca2Bi2 tetrahedra, corners with four equivalent O(3)Ca3Bi2 trigonal bipyramids, edges with two equivalent O(1)Ca4Bi2 octahedra, edges with two equivalent O(2)Ca2Bi2 tetrahedra, and faces with four equivalent O(3)Ca3Bi2 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Bi(1) atoms to form distorted OCa2Bi2 tetrahedra that share corners with four equivalent O(1)Ca4Bi2 octahedra, corners with four equivalent O(2)Ca2Bi2 tetrahedra, corners with six equivalent O(3)Ca3Bi2 trigonal bipyramids,  an edgeedge with one O(1)Ca4Bi2 octahedra, and edges with two equivalent O(3)Ca3Bi2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 12-80°. In the third O site, O(3) is bonded to three equivalent Ca(1) and two equivalent Bi(1) atoms to form distorted OCa3Bi2 trigonal bipyramids that share corners with two equivalent O(1)Ca4Bi2 octahedra, corners with six equivalent O(2)Ca2Bi2 tetrahedra, corners with six equivalent O(3)Ca3Bi2 trigonal bipyramids, edges with two equivalent O(2)Ca2Bi2 tetrahedra,  an edgeedge with one O(3)Ca3Bi2 trigonal bipyramid, and faces with two equivalent O(1)Ca4Bi2 octahedra. The corner-sharing octahedral tilt angles are 55°. is represented by the CIF file [CIF]
data_Ca2Bi2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.434
_cell_length_b   6.531
_cell_length_c   10.272
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   297.469
_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  0.000  0.148  0.371  1.0
  Ca  Ca1  1  0.000  0.852  0.629  1.0
  Ca  Ca2  1  0.000  0.648  0.129  1.0
  Ca  Ca3  1  0.000  0.352  0.871  1.0
  Bi  Bi4  1  0.500  0.206  0.111  1.0
  Bi  Bi5  1  0.500  0.794  0.889  1.0
  Bi  Bi6  1  0.500  0.294  0.611  1.0
  Bi  Bi7  1  0.500  0.706  0.389  1.0
  O  O8  1  0.500  0.500  0.000  1.0
  O  O9  1  0.500  0.176  0.805  1.0
  O  O10  1  0.500  0.676  0.695  1.0
  O  O11  1  0.500  0.324  0.305  1.0
  O  O12  1  0.000  0.212  0.611  1.0
  O  O13  1  0.000  0.788  0.389  1.0
  O  O14  1  0.500  0.824  0.195  1.0
  O  O15  1  0.000  0.288  0.111  1.0
  O  O16  1  0.500  0.000  0.500  1.0
  O  O17  1  0.000  0.712  0.889  1.0
[/CIF]
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The structure described by Ca2Bi2O5 crystallizes in the orthorhombic Pbam space group. Ca(1) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. Bi(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted corner-sharing BiO5 square pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Ca(1) and two equivalent Bi(1) atoms to form distorted OCa4Bi2 octahedra that share corners with eight equivalent O(2)Ca2Bi2 tetrahedra, corners with four equivalent O(3)Ca3Bi2 trigonal bipyramids, edges with two equivalent O(1)Ca4Bi2 octahedra, edges with two equivalent O(2)Ca2Bi2 tetrahedra, and faces with four equivalent O(3)Ca3Bi2 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Bi(1) atoms to form distorted OCa2Bi2 tetrahedra that share corners with four equivalent O(1)Ca4Bi2 octahedra, corners with four equivalent O(2)Ca2Bi2 tetrahedra, corners with six equivalent O(3)Ca3Bi2 trigonal bipyramids,  an edgeedge with one O(1)Ca4Bi2 octahedra, and edges with two equivalent O(3)Ca3Bi2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 12-80°. In the third O site, O(3) is bonded to three equivalent Ca(1) and two equivalent Bi(1) atoms to form distorted OCa3Bi2 trigonal bipyramids that share corners with two equivalent O(1)Ca4Bi2 octahedra, corners with six equivalent O(2)Ca2Bi2 tetrahedra, corners with six equivalent O(3)Ca3Bi2 trigonal bipyramids, edges with two equivalent O(2)Ca2Bi2 tetrahedra,  an edgeedge with one O(3)Ca3Bi2 trigonal bipyramid, and faces with two equivalent O(1)Ca4Bi2 octahedra. The corner-sharing octahedral tilt angles are 55°. is represented by the CIF file [CIF]
data_Ca2Bi2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.434
_cell_length_b   6.531
_cell_length_c   10.272
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   297.469
_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  0.000  0.148  0.371  1.0
  Ca  Ca1  1  0.000  0.852  0.629  1.0
  Ca  Ca2  1  0.000  0.648  0.129  1.0
  Ca  Ca3  1  0.000  0.352  0.871  1.0
  Bi  Bi4  1  0.500  0.206  0.111  1.0
  Bi  Bi5  1  0.500  0.794  0.889  1.0
  Bi  Bi6  1  0.500  0.294  0.611  1.0
  Bi  Bi7  1  0.500  0.706  0.389  1.0
  O  O8  1  0.500  0.500  0.000  1.0
  O  O9  1  0.500  0.176  0.805  1.0
  O  O10  1  0.500  0.676  0.695  1.0
  O  O11  1  0.500  0.324  0.305  1.0
  O  O12  1  0.000  0.212  0.611  1.0
  O  O13  1  0.000  0.788  0.389  1.0
  O  O14  1  0.500  0.824  0.195  1.0
  O  O15  1  0.000  0.288  0.111  1.0
  O  O16  1  0.500  0.000  0.500  1.0
  O  O17  1  0.000  0.712  0.889  1.0
[/CIF]
.