The structure described by NaCaSb2O7 crystallizes in the orthorhombic Imma space group. Na(1) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms to form distorted NaO8 hexagonal bipyramids that share edges with two equivalent Na(1)O8 hexagonal bipyramids, edges with four equivalent Ca(1)O8 hexagonal bipyramids, edges with two equivalent Sb(2)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. Ca(1) is bonded to two equivalent O(1), two equivalent O(4), and four equivalent O(2) atoms to form distorted CaO8 hexagonal bipyramids that share edges with two equivalent Ca(1)O8 hexagonal bipyramids, edges with four equivalent Na(1)O8 hexagonal bipyramids, edges with two equivalent Sb(1)O6 octahedra, and edges with four equivalent Sb(2)O6 octahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, edges with two equivalent Ca(1)O8 hexagonal bipyramids, and edges with four equivalent Na(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 45-46°. In the second Sb site, Sb(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, edges with two equivalent Na(1)O8 hexagonal bipyramids, and edges with four equivalent Ca(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-47°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1) and two equivalent Ca(1) atoms to form ONa2Ca2 tetrahedra that share corners with two equivalent O(4)Ca2Sb2 tetrahedra, corners with two equivalent O(3)Na2Sb2 tetrahedra, corners with four equivalent O(1)Na2Ca2 tetrahedra, corners with eight equivalent O(2)NaCaSb2 tetrahedra,  an edgeedge with one O(4)Ca2Sb2 tetrahedra,  an edgeedge with one O(3)Na2Sb2 tetrahedra, and edges with four equivalent O(2)NaCaSb2 tetrahedra. In the second O site, O(2) is bonded to one Na(1), one Ca(1), one Sb(1), and one Sb(2) atom to form distorted ONaCaSb2 tetrahedra that share corners with two equivalent O(4)Ca2Sb2 tetrahedra, corners with two equivalent O(1)Na2Ca2 tetrahedra, corners with two equivalent O(3)Na2Sb2 tetrahedra, corners with eight equivalent O(2)NaCaSb2 tetrahedra,  an edgeedge with one O(4)Ca2Sb2 tetrahedra,  an edgeedge with one O(1)Na2Ca2 tetrahedra,  an edgeedge with one O(3)Na2Sb2 tetrahedra, and edges with two equivalent O(2)NaCaSb2 tetrahedra. In the third O site, O(3) is bonded to two equivalent Na(1) and two equivalent Sb(1) atoms to form distorted ONa2Sb2 tetrahedra that share corners with two equivalent O(1)Na2Ca2 tetrahedra, corners with four equivalent O(3)Na2Sb2 tetrahedra, corners with eight equivalent O(2)NaCaSb2 tetrahedra,  an edgeedge with one O(1)Na2Ca2 tetrahedra, and edges with four equivalent O(2)NaCaSb2 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent Sb(2) atoms to form distorted OCa2Sb2 tetrahedra that share corners with two equivalent O(1)Na2Ca2 tetrahedra, corners with four equivalent O(4)Ca2Sb2 tetrahedra, corners with eight equivalent O(2)NaCaSb2 tetrahedra,  an edgeedge with one O(1)Na2Ca2 tetrahedra, and edges with four equivalent O(2)NaCaSb2 tetrahedra. is represented by the CIF card [CIF]
data_NaCaSb2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.391
_cell_length_b   7.391
_cell_length_c   7.391
_cell_angle_alpha   119.813
_cell_angle_beta   119.671
_cell_angle_gamma   90.448
_symmetry_Int_Tables_number   1
_cell_volume   286.562
_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
  Na  Na0  1  0.500  0.000  0.000  1.0
  Na  Na1  1  0.500  0.500  0.500  1.0
  Ca  Ca2  1  0.000  0.000  0.000  1.0
  Ca  Ca3  1  0.500  0.000  0.500  1.0
  Sb  Sb4  1  0.000  0.500  0.500  1.0
  Sb  Sb5  1  0.500  0.500  0.000  1.0
  Sb  Sb6  1  0.000  0.000  0.500  1.0
  Sb  Sb7  1  0.000  0.500  0.000  1.0
  O  O8  1  0.368  0.118  0.250  1.0
  O  O9  1  0.632  0.882  0.750  1.0
  O  O10  1  0.676  0.825  0.255  1.0
  O  O11  1  0.070  0.825  0.649  1.0
  O  O12  1  0.677  0.427  0.250  1.0
  O  O13  1  0.070  0.421  0.245  1.0
  O  O14  1  0.676  0.421  0.851  1.0
  O  O15  1  0.078  0.828  0.250  1.0
  O  O16  1  0.324  0.175  0.745  1.0
  O  O17  1  0.930  0.175  0.351  1.0
  O  O18  1  0.323  0.573  0.750  1.0
  O  O19  1  0.930  0.579  0.755  1.0
  O  O20  1  0.324  0.579  0.149  1.0
  O  O21  1  0.922  0.172  0.750  1.0
[/CIF]
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The structure described by NaCaSb2O7 crystallizes in the orthorhombic Imma space group. Na(1) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms to form distorted NaO8 hexagonal bipyramids that share edges with two equivalent Na(1)O8 hexagonal bipyramids, edges with four equivalent Ca(1)O8 hexagonal bipyramids, edges with two equivalent Sb(2)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. Ca(1) is bonded to two equivalent O(1), two equivalent O(4), and four equivalent O(2) atoms to form distorted CaO8 hexagonal bipyramids that share edges with two equivalent Ca(1)O8 hexagonal bipyramids, edges with four equivalent Na(1)O8 hexagonal bipyramids, edges with two equivalent Sb(1)O6 octahedra, and edges with four equivalent Sb(2)O6 octahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, edges with two equivalent Ca(1)O8 hexagonal bipyramids, and edges with four equivalent Na(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 45-46°. In the second Sb site, Sb(2) is bonded to two equivalent O(4) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Sb(2)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, edges with two equivalent Na(1)O8 hexagonal bipyramids, and edges with four equivalent Ca(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-47°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1) and two equivalent Ca(1) atoms to form ONa2Ca2 tetrahedra that share corners with two equivalent O(4)Ca2Sb2 tetrahedra, corners with two equivalent O(3)Na2Sb2 tetrahedra, corners with four equivalent O(1)Na2Ca2 tetrahedra, corners with eight equivalent O(2)NaCaSb2 tetrahedra,  an edgeedge with one O(4)Ca2Sb2 tetrahedra,  an edgeedge with one O(3)Na2Sb2 tetrahedra, and edges with four equivalent O(2)NaCaSb2 tetrahedra. In the second O site, O(2) is bonded to one Na(1), one Ca(1), one Sb(1), and one Sb(2) atom to form distorted ONaCaSb2 tetrahedra that share corners with two equivalent O(4)Ca2Sb2 tetrahedra, corners with two equivalent O(1)Na2Ca2 tetrahedra, corners with two equivalent O(3)Na2Sb2 tetrahedra, corners with eight equivalent O(2)NaCaSb2 tetrahedra,  an edgeedge with one O(4)Ca2Sb2 tetrahedra,  an edgeedge with one O(1)Na2Ca2 tetrahedra,  an edgeedge with one O(3)Na2Sb2 tetrahedra, and edges with two equivalent O(2)NaCaSb2 tetrahedra. In the third O site, O(3) is bonded to two equivalent Na(1) and two equivalent Sb(1) atoms to form distorted ONa2Sb2 tetrahedra that share corners with two equivalent O(1)Na2Ca2 tetrahedra, corners with four equivalent O(3)Na2Sb2 tetrahedra, corners with eight equivalent O(2)NaCaSb2 tetrahedra,  an edgeedge with one O(1)Na2Ca2 tetrahedra, and edges with four equivalent O(2)NaCaSb2 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent Sb(2) atoms to form distorted OCa2Sb2 tetrahedra that share corners with two equivalent O(1)Na2Ca2 tetrahedra, corners with four equivalent O(4)Ca2Sb2 tetrahedra, corners with eight equivalent O(2)NaCaSb2 tetrahedra,  an edgeedge with one O(1)Na2Ca2 tetrahedra, and edges with four equivalent O(2)NaCaSb2 tetrahedra. is represented by the CIF card [CIF]
data_NaCaSb2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.391
_cell_length_b   7.391
_cell_length_c   7.391
_cell_angle_alpha   119.813
_cell_angle_beta   119.671
_cell_angle_gamma   90.448
_symmetry_Int_Tables_number   1
_cell_volume   286.562
_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
  Na  Na0  1  0.500  0.000  0.000  1.0
  Na  Na1  1  0.500  0.500  0.500  1.0
  Ca  Ca2  1  0.000  0.000  0.000  1.0
  Ca  Ca3  1  0.500  0.000  0.500  1.0
  Sb  Sb4  1  0.000  0.500  0.500  1.0
  Sb  Sb5  1  0.500  0.500  0.000  1.0
  Sb  Sb6  1  0.000  0.000  0.500  1.0
  Sb  Sb7  1  0.000  0.500  0.000  1.0
  O  O8  1  0.368  0.118  0.250  1.0
  O  O9  1  0.632  0.882  0.750  1.0
  O  O10  1  0.676  0.825  0.255  1.0
  O  O11  1  0.070  0.825  0.649  1.0
  O  O12  1  0.677  0.427  0.250  1.0
  O  O13  1  0.070  0.421  0.245  1.0
  O  O14  1  0.676  0.421  0.851  1.0
  O  O15  1  0.078  0.828  0.250  1.0
  O  O16  1  0.324  0.175  0.745  1.0
  O  O17  1  0.930  0.175  0.351  1.0
  O  O18  1  0.323  0.573  0.750  1.0
  O  O19  1  0.930  0.579  0.755  1.0
  O  O20  1  0.324  0.579  0.149  1.0
  O  O21  1  0.922  0.172  0.750  1.0
[/CIF]
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