The material described by MgTb2Nb2O8 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Tb sites. In the first Tb site, Tb(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 Tb site, Tb(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 in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to two equivalent O(1), 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 4-coordinate geometry to one Tb(1), one Tb(2), one Nb(1), and one Nb(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(1), one Tb(2), and one Nb(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(1), one Tb(2), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(1), one Tb(2), and one Nb(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb2MgNb2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.924
_cell_length_b   5.924
_cell_length_c   6.214
_cell_angle_alpha   106.755
_cell_angle_beta   106.755
_cell_angle_gamma   107.269
_symmetry_Int_Tables_number   1
_cell_volume   181.976
_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
  Tb  Tb0  1  0.004  0.996  0.000  1.0
  Tb  Tb1  1  0.726  0.274  0.500  1.0
  Mg  Mg2  1  0.029  0.971  0.500  1.0
  Nb  Nb3  1  0.467  0.533  0.000  1.0
  Nb  Nb4  1  0.332  0.668  0.500  1.0
  O  O5  1  0.468  0.395  0.251  1.0
  O  O6  1  0.708  0.889  0.211  1.0
  O  O7  1  0.040  0.325  0.329  1.0
  O  O8  1  0.605  0.532  0.749  1.0
  O  O9  1  0.111  0.292  0.789  1.0
  O  O10  1  0.234  0.890  0.313  1.0
  O  O11  1  0.675  0.960  0.671  1.0
  O  O12  1  0.110  0.766  0.687  1.0
[/CIF]
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The material described by MgTb2Nb2O8 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Tb sites. In the first Tb site, Tb(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 Tb site, Tb(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 in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to two equivalent O(1), 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 4-coordinate geometry to one Tb(1), one Tb(2), one Nb(1), and one Nb(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(1), one Tb(2), and one Nb(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(1), one Tb(2), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Tb(1), one Tb(2), and one Nb(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb2MgNb2O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.924
_cell_length_b   5.924
_cell_length_c   6.214
_cell_angle_alpha   106.755
_cell_angle_beta   106.755
_cell_angle_gamma   107.269
_symmetry_Int_Tables_number   1
_cell_volume   181.976
_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
  Tb  Tb0  1  0.004  0.996  0.000  1.0
  Tb  Tb1  1  0.726  0.274  0.500  1.0
  Mg  Mg2  1  0.029  0.971  0.500  1.0
  Nb  Nb3  1  0.467  0.533  0.000  1.0
  Nb  Nb4  1  0.332  0.668  0.500  1.0
  O  O5  1  0.468  0.395  0.251  1.0
  O  O6  1  0.708  0.889  0.211  1.0
  O  O7  1  0.040  0.325  0.329  1.0
  O  O8  1  0.605  0.532  0.749  1.0
  O  O9  1  0.111  0.292  0.789  1.0
  O  O10  1  0.234  0.890  0.313  1.0
  O  O11  1  0.675  0.960  0.671  1.0
  O  O12  1  0.110  0.766  0.687  1.0
[/CIF]
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