The material structure described by Ca2Nb2SbO8 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one O(6), one O(7), two equivalent O(5), and two equivalent O(8) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(5), one O(8), two equivalent O(6), and two equivalent O(7) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(8) atom to form distorted edge-sharing NbO6 octahedra. In the second Nb site, Nb(2) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form edge-sharing NbO6 octahedra. Sb(1) is bonded in a see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Nb(1), one Nb(2), and one Sb(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Nb(1), one Nb(2), and one Sb(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Nb(1) and one Sb(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one Sb(1) atom. In the fifth O site, O(5) is bonded to one Ca(2), two equivalent Ca(1), one Nb(1), and one Nb(2) atom to form distorted OCa3Nb2 trigonal bipyramids that share  a cornercorner with one O(7)Ca3Nb trigonal pyramid, corners with two equivalent O(8)Ca3Nb trigonal pyramids,  an edgeedge with one O(5)Ca3Nb2 trigonal bipyramid, edges with two equivalent O(7)Ca3Nb trigonal pyramids, and edges with two equivalent O(8)Ca3Nb trigonal pyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nb(1), and one Nb(2) atom. In the seventh O site, O(7) is bonded to one Ca(1), two equivalent Ca(2), and one Nb(2) atom to form distorted OCa3Nb trigonal pyramids that share  a cornercorner with one O(5)Ca3Nb2 trigonal bipyramid, corners with four equivalent O(8)Ca3Nb trigonal pyramids, edges with two equivalent O(5)Ca3Nb2 trigonal bipyramids, and  an edgeedge with one O(7)Ca3Nb trigonal pyramid. In the eighth O site, O(8) is bonded to one Ca(2), two equivalent Ca(1), and one Nb(1) atom to form distorted OCa3Nb trigonal pyramids that share corners with two equivalent O(5)Ca3Nb2 trigonal bipyramids, corners with four equivalent O(7)Ca3Nb trigonal pyramids, edges with two equivalent O(5)Ca3Nb2 trigonal bipyramids, and  an edgeedge with one O(8)Ca3Nb trigonal pyramid. is represented by the CIF file [CIF]
data_Ca2Nb2SbO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.499
_cell_length_b   6.926
_cell_length_c   10.282
_cell_angle_alpha   71.262
_cell_angle_beta   88.431
_cell_angle_gamma   88.416
_symmetry_Int_Tables_number   1
_cell_volume   370.592
_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  0.251  0.447  0.419  1.0
  Ca  Ca1  1  0.241  0.859  0.575  1.0
  Ca  Ca2  1  0.749  0.553  0.581  1.0
  Ca  Ca3  1  0.759  0.141  0.425  1.0
  Nb  Nb4  1  0.258  0.257  0.757  1.0
  Nb  Nb5  1  0.263  0.002  0.247  1.0
  Nb  Nb6  1  0.742  0.743  0.243  1.0
  Nb  Nb7  1  0.737  0.998  0.753  1.0
  Sb  Sb8  1  0.228  0.689  0.995  1.0
  Sb  Sb9  1  0.772  0.311  0.005  1.0
  O  O10  1  0.901  0.200  0.854  1.0
  O  O11  1  0.606  0.056  0.139  1.0
  O  O12  1  0.099  0.800  0.146  1.0
  O  O13  1  0.394  0.944  0.861  1.0
  O  O14  1  0.416  0.379  0.864  1.0
  O  O15  1  0.079  0.221  0.123  1.0
  O  O16  1  0.584  0.621  0.136  1.0
  O  O17  1  0.921  0.779  0.877  1.0
  O  O18  1  0.524  0.256  0.614  1.0
  O  O19  1  0.976  0.886  0.375  1.0
  O  O20  1  0.643  0.852  0.631  1.0
  O  O21  1  0.849  0.479  0.378  1.0
  O  O22  1  0.357  0.148  0.369  1.0
  O  O23  1  0.151  0.521  0.622  1.0
  O  O24  1  0.024  0.114  0.625  1.0
  O  O25  1  0.476  0.744  0.386  1.0
[/CIF]
.
The material structure described by Ca2Nb2SbO8 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 5-coordinate geometry to one O(6), one O(7), two equivalent O(5), and two equivalent O(8) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(5), one O(8), two equivalent O(6), and two equivalent O(7) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(8) atom to form distorted edge-sharing NbO6 octahedra. In the second Nb site, Nb(2) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form edge-sharing NbO6 octahedra. Sb(1) is bonded in a see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Nb(1), one Nb(2), and one Sb(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Nb(1), one Nb(2), and one Sb(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Nb(1) and one Sb(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one Sb(1) atom. In the fifth O site, O(5) is bonded to one Ca(2), two equivalent Ca(1), one Nb(1), and one Nb(2) atom to form distorted OCa3Nb2 trigonal bipyramids that share  a cornercorner with one O(7)Ca3Nb trigonal pyramid, corners with two equivalent O(8)Ca3Nb trigonal pyramids,  an edgeedge with one O(5)Ca3Nb2 trigonal bipyramid, edges with two equivalent O(7)Ca3Nb trigonal pyramids, and edges with two equivalent O(8)Ca3Nb trigonal pyramids. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nb(1), and one Nb(2) atom. In the seventh O site, O(7) is bonded to one Ca(1), two equivalent Ca(2), and one Nb(2) atom to form distorted OCa3Nb trigonal pyramids that share  a cornercorner with one O(5)Ca3Nb2 trigonal bipyramid, corners with four equivalent O(8)Ca3Nb trigonal pyramids, edges with two equivalent O(5)Ca3Nb2 trigonal bipyramids, and  an edgeedge with one O(7)Ca3Nb trigonal pyramid. In the eighth O site, O(8) is bonded to one Ca(2), two equivalent Ca(1), and one Nb(1) atom to form distorted OCa3Nb trigonal pyramids that share corners with two equivalent O(5)Ca3Nb2 trigonal bipyramids, corners with four equivalent O(7)Ca3Nb trigonal pyramids, edges with two equivalent O(5)Ca3Nb2 trigonal bipyramids, and  an edgeedge with one O(8)Ca3Nb trigonal pyramid. is represented by the CIF file [CIF]
data_Ca2Nb2SbO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.499
_cell_length_b   6.926
_cell_length_c   10.282
_cell_angle_alpha   71.262
_cell_angle_beta   88.431
_cell_angle_gamma   88.416
_symmetry_Int_Tables_number   1
_cell_volume   370.592
_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  0.251  0.447  0.419  1.0
  Ca  Ca1  1  0.241  0.859  0.575  1.0
  Ca  Ca2  1  0.749  0.553  0.581  1.0
  Ca  Ca3  1  0.759  0.141  0.425  1.0
  Nb  Nb4  1  0.258  0.257  0.757  1.0
  Nb  Nb5  1  0.263  0.002  0.247  1.0
  Nb  Nb6  1  0.742  0.743  0.243  1.0
  Nb  Nb7  1  0.737  0.998  0.753  1.0
  Sb  Sb8  1  0.228  0.689  0.995  1.0
  Sb  Sb9  1  0.772  0.311  0.005  1.0
  O  O10  1  0.901  0.200  0.854  1.0
  O  O11  1  0.606  0.056  0.139  1.0
  O  O12  1  0.099  0.800  0.146  1.0
  O  O13  1  0.394  0.944  0.861  1.0
  O  O14  1  0.416  0.379  0.864  1.0
  O  O15  1  0.079  0.221  0.123  1.0
  O  O16  1  0.584  0.621  0.136  1.0
  O  O17  1  0.921  0.779  0.877  1.0
  O  O18  1  0.524  0.256  0.614  1.0
  O  O19  1  0.976  0.886  0.375  1.0
  O  O20  1  0.643  0.852  0.631  1.0
  O  O21  1  0.849  0.479  0.378  1.0
  O  O22  1  0.357  0.148  0.369  1.0
  O  O23  1  0.151  0.521  0.622  1.0
  O  O24  1  0.024  0.114  0.625  1.0
  O  O25  1  0.476  0.744  0.386  1.0
[/CIF]
.