The material described by Ca2Nb2BiO8 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. Nb(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form distorted NbO6 octahedra that share corners with four equivalent Bi(1)O6 octahedra and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-57°. Bi(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form BiO6 octahedra that share corners with eight equivalent Nb(1)O6 octahedra and edges with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-57°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Nb(1) and one Bi(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Ca(1) and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded to three equivalent Ca(1) and one Nb(1) atom to form a mixture of distorted corner and edge-sharing OCa3Nb trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2Nb2BiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.596
_cell_length_b   10.596
_cell_length_c   5.584
_cell_angle_alpha   88.903
_cell_angle_beta   88.903
_cell_angle_gamma   36.381
_symmetry_Int_Tables_number   1
_cell_volume   371.824
_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  0.873  0.558  0.754  1.0
  Ca  Ca1  1  0.442  0.127  0.746  1.0
  Ca  Ca2  1  0.127  0.442  0.246  1.0
  Ca  Ca3  1  0.558  0.873  0.254  1.0
  Nb  Nb4  1  0.028  0.732  0.742  1.0
  Nb  Nb5  1  0.268  0.972  0.758  1.0
  Nb  Nb6  1  0.972  0.268  0.258  1.0
  Nb  Nb7  1  0.732  0.028  0.242  1.0
  Bi  Bi8  1  0.677  0.323  0.750  1.0
  Bi  Bi9  1  0.323  0.677  0.250  1.0
  O  O10  1  0.029  0.825  0.062  1.0
  O  O11  1  0.175  0.971  0.438  1.0
  O  O12  1  0.971  0.175  0.938  1.0
  O  O13  1  0.825  0.029  0.562  1.0
  O  O14  1  0.290  0.582  0.607  1.0
  O  O15  1  0.418  0.710  0.893  1.0
  O  O16  1  0.710  0.418  0.393  1.0
  O  O17  1  0.582  0.290  0.107  1.0
  O  O18  1  0.893  0.738  0.472  1.0
  O  O19  1  0.262  0.107  0.028  1.0
  O  O20  1  0.474  0.148  0.352  1.0
  O  O21  1  0.852  0.526  0.148  1.0
  O  O22  1  0.526  0.852  0.648  1.0
  O  O23  1  0.148  0.474  0.852  1.0
  O  O24  1  0.738  0.893  0.972  1.0
  O  O25  1  0.107  0.262  0.528  1.0
[/CIF]
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The material described by Ca2Nb2BiO8 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 6-coordinate geometry to three equivalent O(3) and three equivalent O(4) atoms. Nb(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form distorted NbO6 octahedra that share corners with four equivalent Bi(1)O6 octahedra and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-57°. Bi(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form BiO6 octahedra that share corners with eight equivalent Nb(1)O6 octahedra and edges with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-57°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Nb(1) and one Bi(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Ca(1) and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded to three equivalent Ca(1) and one Nb(1) atom to form a mixture of distorted corner and edge-sharing OCa3Nb trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2Nb2BiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.596
_cell_length_b   10.596
_cell_length_c   5.584
_cell_angle_alpha   88.903
_cell_angle_beta   88.903
_cell_angle_gamma   36.381
_symmetry_Int_Tables_number   1
_cell_volume   371.824
_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  0.873  0.558  0.754  1.0
  Ca  Ca1  1  0.442  0.127  0.746  1.0
  Ca  Ca2  1  0.127  0.442  0.246  1.0
  Ca  Ca3  1  0.558  0.873  0.254  1.0
  Nb  Nb4  1  0.028  0.732  0.742  1.0
  Nb  Nb5  1  0.268  0.972  0.758  1.0
  Nb  Nb6  1  0.972  0.268  0.258  1.0
  Nb  Nb7  1  0.732  0.028  0.242  1.0
  Bi  Bi8  1  0.677  0.323  0.750  1.0
  Bi  Bi9  1  0.323  0.677  0.250  1.0
  O  O10  1  0.029  0.825  0.062  1.0
  O  O11  1  0.175  0.971  0.438  1.0
  O  O12  1  0.971  0.175  0.938  1.0
  O  O13  1  0.825  0.029  0.562  1.0
  O  O14  1  0.290  0.582  0.607  1.0
  O  O15  1  0.418  0.710  0.893  1.0
  O  O16  1  0.710  0.418  0.393  1.0
  O  O17  1  0.582  0.290  0.107  1.0
  O  O18  1  0.893  0.738  0.472  1.0
  O  O19  1  0.262  0.107  0.028  1.0
  O  O20  1  0.474  0.148  0.352  1.0
  O  O21  1  0.852  0.526  0.148  1.0
  O  O22  1  0.526  0.852  0.648  1.0
  O  O23  1  0.148  0.474  0.852  1.0
  O  O24  1  0.738  0.893  0.972  1.0
  O  O25  1  0.107  0.262  0.528  1.0
[/CIF]
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