The crystal structure described by Mg2Nb2TeO8 crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(6), one O(7), two equivalent O(5), and two equivalent O(8) atoms to form distorted MgO6 octahedra that share corners with four equivalent Nb(2)O6 octahedra and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-57°. In the second Mg site, Mg(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 in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(8) atom. 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 NbO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-57°. Te(1) is bonded in a 3-coordinate geometry to one O(4) and two equivalent O(3) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Nb(1) and one Nb(2) atom. In the second O site, O(2) is bonded in a water-like geometry to one Nb(1) and one Nb(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Nb(1) and two equivalent Te(1) atoms. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one Te(1) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Mg(2), two equivalent Mg(1), one Nb(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), one Nb(1), and one Nb(2) atom. In the seventh O site, O(7) is bonded to one Mg(1), two equivalent Mg(2), and one Nb(2) atom to form a mixture of corner and edge-sharing OMg3Nb trigonal pyramids. In the eighth O site, O(8) is bonded to one Mg(2), two equivalent Mg(1), and one Nb(1) atom to form a mixture of corner and edge-sharing OMg3Nb trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Nb2TeO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.215
_cell_length_b   6.167
_cell_length_c   11.426
_cell_angle_alpha   101.955
_cell_angle_beta   96.177
_cell_angle_gamma   89.794
_symmetry_Int_Tables_number   1
_cell_volume   357.338
_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
  Mg  Mg0  1  0.759  0.398  0.533  1.0
  Mg  Mg1  1  0.749  0.876  0.455  1.0
  Mg  Mg2  1  0.241  0.602  0.467  1.0
  Mg  Mg3  1  0.251  0.124  0.545  1.0
  Nb  Nb4  1  0.700  0.336  0.260  1.0
  Nb  Nb5  1  0.780  0.975  0.720  1.0
  Nb  Nb6  1  0.300  0.664  0.740  1.0
  Nb  Nb7  1  0.220  0.025  0.280  1.0
  Te  Te8  1  0.825  0.661  0.020  1.0
  Te  Te9  1  0.175  0.339  0.980  1.0
  O  O10  1  0.009  0.239  0.191  1.0
  O  O11  1  0.486  0.960  0.807  1.0
  O  O12  1  0.991  0.761  0.809  1.0
  O  O13  1  0.514  0.040  0.193  1.0
  O  O14  1  0.542  0.492  0.151  1.0
  O  O15  1  0.963  0.224  0.827  1.0
  O  O16  1  0.458  0.508  0.849  1.0
  O  O17  1  0.037  0.776  0.173  1.0
  O  O18  1  0.427  0.320  0.389  1.0
  O  O19  1  0.057  0.883  0.601  1.0
  O  O20  1  0.367  0.859  0.401  1.0
  O  O21  1  0.139  0.434  0.605  1.0
  O  O22  1  0.633  0.141  0.599  1.0
  O  O23  1  0.861  0.566  0.395  1.0
  O  O24  1  0.943  0.117  0.399  1.0
  O  O25  1  0.573  0.680  0.611  1.0
[/CIF]
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The crystal structure described by Mg2Nb2TeO8 crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(6), one O(7), two equivalent O(5), and two equivalent O(8) atoms to form distorted MgO6 octahedra that share corners with four equivalent Nb(2)O6 octahedra and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-57°. In the second Mg site, Mg(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 in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(8) atom. 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 NbO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-57°. Te(1) is bonded in a 3-coordinate geometry to one O(4) and two equivalent O(3) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Nb(1) and one Nb(2) atom. In the second O site, O(2) is bonded in a water-like geometry to one Nb(1) and one Nb(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Nb(1) and two equivalent Te(1) atoms. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Nb(2) and one Te(1) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Mg(2), two equivalent Mg(1), one Nb(1), and one Nb(2) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Mg(1), two equivalent Mg(2), one Nb(1), and one Nb(2) atom. In the seventh O site, O(7) is bonded to one Mg(1), two equivalent Mg(2), and one Nb(2) atom to form a mixture of corner and edge-sharing OMg3Nb trigonal pyramids. In the eighth O site, O(8) is bonded to one Mg(2), two equivalent Mg(1), and one Nb(1) atom to form a mixture of corner and edge-sharing OMg3Nb trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Nb2TeO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.215
_cell_length_b   6.167
_cell_length_c   11.426
_cell_angle_alpha   101.955
_cell_angle_beta   96.177
_cell_angle_gamma   89.794
_symmetry_Int_Tables_number   1
_cell_volume   357.338
_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
  Mg  Mg0  1  0.759  0.398  0.533  1.0
  Mg  Mg1  1  0.749  0.876  0.455  1.0
  Mg  Mg2  1  0.241  0.602  0.467  1.0
  Mg  Mg3  1  0.251  0.124  0.545  1.0
  Nb  Nb4  1  0.700  0.336  0.260  1.0
  Nb  Nb5  1  0.780  0.975  0.720  1.0
  Nb  Nb6  1  0.300  0.664  0.740  1.0
  Nb  Nb7  1  0.220  0.025  0.280  1.0
  Te  Te8  1  0.825  0.661  0.020  1.0
  Te  Te9  1  0.175  0.339  0.980  1.0
  O  O10  1  0.009  0.239  0.191  1.0
  O  O11  1  0.486  0.960  0.807  1.0
  O  O12  1  0.991  0.761  0.809  1.0
  O  O13  1  0.514  0.040  0.193  1.0
  O  O14  1  0.542  0.492  0.151  1.0
  O  O15  1  0.963  0.224  0.827  1.0
  O  O16  1  0.458  0.508  0.849  1.0
  O  O17  1  0.037  0.776  0.173  1.0
  O  O18  1  0.427  0.320  0.389  1.0
  O  O19  1  0.057  0.883  0.601  1.0
  O  O20  1  0.367  0.859  0.401  1.0
  O  O21  1  0.139  0.434  0.605  1.0
  O  O22  1  0.633  0.141  0.599  1.0
  O  O23  1  0.861  0.566  0.395  1.0
  O  O24  1  0.943  0.117  0.399  1.0
  O  O25  1  0.573  0.680  0.611  1.0
[/CIF]
.