The structure described by Ca2Nb2NiO8 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(4), and four equivalent O(3) atoms. Nb(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms. Ni(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), two equivalent Nb(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a 6-coordinate geometry to four 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 CIF card [CIF]
data_Ca2Nb2NiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.956
_cell_length_b   9.956
_cell_length_c   5.485
_cell_angle_alpha   88.826
_cell_angle_beta   88.826
_cell_angle_gamma   36.909
_symmetry_Int_Tables_number   1
_cell_volume   326.422
_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  0.891  0.523  0.758  1.0
  Ca  Ca1  1  0.477  0.109  0.742  1.0
  Ca  Ca2  1  0.109  0.477  0.242  1.0
  Ca  Ca3  1  0.523  0.891  0.258  1.0
  Nb  Nb4  1  0.045  0.735  0.755  1.0
  Nb  Nb5  1  0.265  0.955  0.745  1.0
  Nb  Nb6  1  0.955  0.265  0.245  1.0
  Nb  Nb7  1  0.735  0.045  0.255  1.0
  Ni  Ni8  1  0.641  0.359  0.750  1.0
  Ni  Ni9  1  0.359  0.641  0.250  1.0
  O  O10  1  0.061  0.802  0.094  1.0
  O  O11  1  0.198  0.939  0.406  1.0
  O  O12  1  0.939  0.198  0.906  1.0
  O  O13  1  0.802  0.061  0.594  1.0
  O  O14  1  0.302  0.586  0.581  1.0
  O  O15  1  0.414  0.698  0.919  1.0
  O  O16  1  0.698  0.414  0.419  1.0
  O  O17  1  0.586  0.302  0.081  1.0
  O  O18  1  0.877  0.760  0.507  1.0
  O  O19  1  0.240  0.123  0.993  1.0
  O  O20  1  0.464  0.167  0.343  1.0
  O  O21  1  0.833  0.536  0.157  1.0
  O  O22  1  0.536  0.833  0.657  1.0
  O  O23  1  0.167  0.464  0.843  1.0
  O  O24  1  0.760  0.877  0.007  1.0
  O  O25  1  0.123  0.240  0.493  1.0
[/CIF]
.
The structure described by Ca2Nb2NiO8 crystallizes in the monoclinic C2/c space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), three equivalent O(4), and four equivalent O(3) atoms. Nb(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms. Ni(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing NiO6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ca(1), two equivalent Nb(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a 6-coordinate geometry to four 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 CIF card [CIF]
data_Ca2Nb2NiO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.956
_cell_length_b   9.956
_cell_length_c   5.485
_cell_angle_alpha   88.826
_cell_angle_beta   88.826
_cell_angle_gamma   36.909
_symmetry_Int_Tables_number   1
_cell_volume   326.422
_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  0.891  0.523  0.758  1.0
  Ca  Ca1  1  0.477  0.109  0.742  1.0
  Ca  Ca2  1  0.109  0.477  0.242  1.0
  Ca  Ca3  1  0.523  0.891  0.258  1.0
  Nb  Nb4  1  0.045  0.735  0.755  1.0
  Nb  Nb5  1  0.265  0.955  0.745  1.0
  Nb  Nb6  1  0.955  0.265  0.245  1.0
  Nb  Nb7  1  0.735  0.045  0.255  1.0
  Ni  Ni8  1  0.641  0.359  0.750  1.0
  Ni  Ni9  1  0.359  0.641  0.250  1.0
  O  O10  1  0.061  0.802  0.094  1.0
  O  O11  1  0.198  0.939  0.406  1.0
  O  O12  1  0.939  0.198  0.906  1.0
  O  O13  1  0.802  0.061  0.594  1.0
  O  O14  1  0.302  0.586  0.581  1.0
  O  O15  1  0.414  0.698  0.919  1.0
  O  O16  1  0.698  0.414  0.419  1.0
  O  O17  1  0.586  0.302  0.081  1.0
  O  O18  1  0.877  0.760  0.507  1.0
  O  O19  1  0.240  0.123  0.993  1.0
  O  O20  1  0.464  0.167  0.343  1.0
  O  O21  1  0.833  0.536  0.157  1.0
  O  O22  1  0.536  0.833  0.657  1.0
  O  O23  1  0.167  0.464  0.843  1.0
  O  O24  1  0.760  0.877  0.007  1.0
  O  O25  1  0.123  0.240  0.493  1.0
[/CIF]
.