The compound described by MgNd2Nb2O8 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share  an edgeedge with one Nb(1)O4 tetrahedra. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Nd site, Nd(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form distorted NbO4 tetrahedra that share  an edgeedge with one Mg(1)O6 octahedra. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Nd(1), one Nd(2), and one Nb(1) atom. In the second O site, O(2) is bonded to one Mg(1), one Nd(1), one Nd(2), and one Nb(2) atom to form a mixture of distorted edge and corner-sharing ONd2MgNb trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Nd(1), one Nd(2), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), one Nd(1), one Nd(2), one Nb(1), and one Nb(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nd2MgNb2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.427
_cell_length_b   5.674
_cell_length_c   6.985
_cell_angle_alpha   113.326
_cell_angle_beta   112.214
_cell_angle_gamma   91.495
_symmetry_Int_Tables_number   1
_cell_volume   178.897
_cell_formula_units_Z   1
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
  Nd  Nd0  1  0.133  0.383  0.765  1.0
  Nd  Nd1  1  0.890  0.639  0.279  1.0
  Mg  Mg2  1  0.838  0.088  0.176  1.0
  Nb  Nb3  1  0.608  0.858  0.716  1.0
  Nb  Nb4  1  0.352  0.102  0.203  1.0
  O  O5  1  0.813  0.970  0.586  1.0
  O  O6  1  0.274  0.615  0.586  1.0
  O  O7  1  0.186  0.052  0.408  1.0
  O  O8  1  0.723  0.356  0.408  1.0
  O  O9  1  0.092  0.304  0.094  1.0
  O  O10  1  0.502  0.789  0.094  1.0
  O  O11  1  0.915  0.761  0.940  1.0
  O  O12  1  0.525  0.178  0.940  1.0
[/CIF]
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The compound described by MgNd2Nb2O8 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share  an edgeedge with one Nb(1)O4 tetrahedra. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second Nd site, Nd(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form distorted NbO4 tetrahedra that share  an edgeedge with one Mg(1)O6 octahedra. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Nd(1), one Nd(2), and one Nb(1) atom. In the second O site, O(2) is bonded to one Mg(1), one Nd(1), one Nd(2), and one Nb(2) atom to form a mixture of distorted edge and corner-sharing ONd2MgNb trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Nd(1), one Nd(2), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(1), one Nd(1), one Nd(2), one Nb(1), and one Nb(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nd2MgNb2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.427
_cell_length_b   5.674
_cell_length_c   6.985
_cell_angle_alpha   113.326
_cell_angle_beta   112.214
_cell_angle_gamma   91.495
_symmetry_Int_Tables_number   1
_cell_volume   178.897
_cell_formula_units_Z   1
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
  Nd  Nd0  1  0.133  0.383  0.765  1.0
  Nd  Nd1  1  0.890  0.639  0.279  1.0
  Mg  Mg2  1  0.838  0.088  0.176  1.0
  Nb  Nb3  1  0.608  0.858  0.716  1.0
  Nb  Nb4  1  0.352  0.102  0.203  1.0
  O  O5  1  0.813  0.970  0.586  1.0
  O  O6  1  0.274  0.615  0.586  1.0
  O  O7  1  0.186  0.052  0.408  1.0
  O  O8  1  0.723  0.356  0.408  1.0
  O  O9  1  0.092  0.304  0.094  1.0
  O  O10  1  0.502  0.789  0.094  1.0
  O  O11  1  0.915  0.761  0.940  1.0
  O  O12  1  0.525  0.178  0.940  1.0
[/CIF]
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