The crystal structure described by Ca2NdNbO6 crystallizes in the monoclinic Pc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form CaO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-42°. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(6), two equivalent O(1), and two equivalent O(5) atoms. Nd(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one O(5), two equivalent O(2), and two equivalent O(6) atoms. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NbO6 octahedra that share corners with six equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-42°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nd(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), two equivalent Nd(1), and one Nb(1) atom. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), one Nd(1), and one Nb(1) atom to form distorted corner-sharing OCa2NdNb tetrahedra. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Nd(1), and one Nb(1) atom to form distorted corner-sharing OCa2NdNb tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nd(1), and one Nb(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), two equivalent Nd(1), and one Nb(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2NdNbO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.663
_cell_length_b   5.950
_cell_length_c   8.223
_cell_angle_alpha   90.000
_cell_angle_beta   90.173
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   277.068
_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  0.999  0.997  0.500  1.0
  Ca  Ca1  1  0.499  0.503  1.000  1.0
  Ca  Ca2  1  0.514  0.944  0.245  1.0
  Ca  Ca3  1  0.014  0.556  0.745  1.0
  Nd  Nd4  1  0.484  0.058  0.756  1.0
  Nd  Nd5  1  0.984  0.442  0.256  1.0
  Nb  Nb6  1  0.500  0.501  0.502  1.0
  Nb  Nb7  1  1.000  0.999  0.002  1.0
  O  O8  1  0.831  0.712  0.073  1.0
  O  O9  1  0.331  0.788  0.573  1.0
  O  O10  1  0.173  0.282  0.928  1.0
  O  O11  1  0.673  0.218  0.428  1.0
  O  O12  1  0.377  0.557  0.270  1.0
  O  O13  1  0.877  0.943  0.770  1.0
  O  O14  1  0.618  0.443  0.730  1.0
  O  O15  1  0.118  0.057  0.230  1.0
  O  O16  1  0.794  0.675  0.445  1.0
  O  O17  1  0.294  0.825  0.945  1.0
  O  O18  1  0.209  0.321  0.553  1.0
  O  O19  1  0.709  0.179  0.053  1.0
[/CIF]
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The crystal structure described by Ca2NdNbO6 crystallizes in the monoclinic Pc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form CaO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-42°. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(6), two equivalent O(1), and two equivalent O(5) atoms. Nd(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one O(5), two equivalent O(2), and two equivalent O(6) atoms. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NbO6 octahedra that share corners with six equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-42°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nd(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), two equivalent Nd(1), and one Nb(1) atom. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), one Nd(1), and one Nb(1) atom to form distorted corner-sharing OCa2NdNb tetrahedra. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Nd(1), and one Nb(1) atom to form distorted corner-sharing OCa2NdNb tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nd(1), and one Nb(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), two equivalent Nd(1), and one Nb(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca2NdNbO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.663
_cell_length_b   5.950
_cell_length_c   8.223
_cell_angle_alpha   90.000
_cell_angle_beta   90.173
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   277.068
_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  0.999  0.997  0.500  1.0
  Ca  Ca1  1  0.499  0.503  1.000  1.0
  Ca  Ca2  1  0.514  0.944  0.245  1.0
  Ca  Ca3  1  0.014  0.556  0.745  1.0
  Nd  Nd4  1  0.484  0.058  0.756  1.0
  Nd  Nd5  1  0.984  0.442  0.256  1.0
  Nb  Nb6  1  0.500  0.501  0.502  1.0
  Nb  Nb7  1  1.000  0.999  0.002  1.0
  O  O8  1  0.831  0.712  0.073  1.0
  O  O9  1  0.331  0.788  0.573  1.0
  O  O10  1  0.173  0.282  0.928  1.0
  O  O11  1  0.673  0.218  0.428  1.0
  O  O12  1  0.377  0.557  0.270  1.0
  O  O13  1  0.877  0.943  0.770  1.0
  O  O14  1  0.618  0.443  0.730  1.0
  O  O15  1  0.118  0.057  0.230  1.0
  O  O16  1  0.794  0.675  0.445  1.0
  O  O17  1  0.294  0.825  0.945  1.0
  O  O18  1  0.209  0.321  0.553  1.0
  O  O19  1  0.709  0.179  0.053  1.0
[/CIF]
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