The compound described by Ba2MgNb4O12 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to two equivalent O(10), two equivalent O(11), and two equivalent O(5) atoms. In the second Ba site, Ba(2) is bonded in a 4-coordinate geometry to one O(1), one O(4), two equivalent O(2), two equivalent O(3), and two equivalent O(8) atoms. Mg(1) is bonded in a 2-coordinate geometry to one O(1), one O(4), two equivalent O(2), two equivalent O(3), and two equivalent O(8) atoms. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(3), one O(8), one O(9), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 7-30°. In the second Nb site, Nb(2) is bonded to one O(12), one O(2), one O(5), one O(8), and two equivalent O(1) atoms to form a mixture of corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 8-30°. In the third Nb site, Nb(3) is bonded to one O(11), one O(12), one O(2), one O(5), and two equivalent O(6) atoms to form a mixture of corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 2-41°. In the fourth Nb site, Nb(4) is bonded to one O(10), one O(11), one O(3), one O(9), and two equivalent O(7) atoms to form a mixture of corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 2-41°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Ba(2), one Mg(1), and two equivalent Nb(2) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(2), two equivalent Mg(1), one Nb(2), and one Nb(3) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(2), two equivalent Mg(1), one Nb(1), and one Nb(4) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ba(2), one Mg(1), and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Nb(2), and one Nb(3) atom. In the sixth O site, O(6) is bonded in a linear geometry to two equivalent Nb(3) atoms. In the seventh O site, O(7) is bonded in a linear geometry to two equivalent Nb(4) atoms. In the eighth O site, O(8) is bonded to two equivalent Ba(2), two equivalent Mg(1), one Nb(1), and one Nb(2) atom to form distorted edge-sharing OBa2Mg2Nb2 octahedra. In the ninth O site, O(9) is bonded in a linear geometry to one Nb(1) and one Nb(4) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Nb(1), and one Nb(4) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Nb(3), and one Nb(4) atom. In the twelfth O site, O(12) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. is represented by the CIF file [CIF]
data_Ba2MgNb4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.988
_cell_length_b   6.577
_cell_length_c   10.456
_cell_angle_alpha   89.959
_cell_angle_beta   90.005
_cell_angle_gamma   90.042
_symmetry_Int_Tables_number   1
_cell_volume   274.225
_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
  Ba  Ba0  1  0.000  0.344  0.751  1.0
  Ba  Ba1  1  0.001  0.575  0.250  1.0
  Mg  Mg2  1  0.998  0.057  0.250  1.0
  Nb  Nb3  1  0.500  0.216  0.055  1.0
  Nb  Nb4  1  0.500  0.217  0.445  1.0
  Nb  Nb5  1  0.500  0.783  0.569  1.0
  Nb  Nb6  1  0.500  0.784  0.933  1.0
  O  O7  1  0.000  0.227  0.412  1.0
  O  O8  1  0.500  0.913  0.379  1.0
  O  O9  1  0.500  0.912  0.121  1.0
  O  O10  1  0.000  0.226  0.088  1.0
  O  O11  1  0.500  0.110  0.616  1.0
  O  O12  1  0.000  0.789  0.567  1.0
  O  O13  1  0.000  0.789  0.934  1.0
  O  O14  1  0.500  0.298  0.250  1.0
  O  O15  1  0.500  0.507  0.004  1.0
  O  O16  1  0.500  0.111  0.882  1.0
  O  O17  1  0.500  0.676  0.750  1.0
  O  O18  1  0.500  0.508  0.494  1.0
[/CIF]
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The compound described by Ba2MgNb4O12 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 6-coordinate geometry to two equivalent O(10), two equivalent O(11), and two equivalent O(5) atoms. In the second Ba site, Ba(2) is bonded in a 4-coordinate geometry to one O(1), one O(4), two equivalent O(2), two equivalent O(3), and two equivalent O(8) atoms. Mg(1) is bonded in a 2-coordinate geometry to one O(1), one O(4), two equivalent O(2), two equivalent O(3), and two equivalent O(8) atoms. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(3), one O(8), one O(9), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 7-30°. In the second Nb site, Nb(2) is bonded to one O(12), one O(2), one O(5), one O(8), and two equivalent O(1) atoms to form a mixture of corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 8-30°. In the third Nb site, Nb(3) is bonded to one O(11), one O(12), one O(2), one O(5), and two equivalent O(6) atoms to form a mixture of corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 2-41°. In the fourth Nb site, Nb(4) is bonded to one O(10), one O(11), one O(3), one O(9), and two equivalent O(7) atoms to form a mixture of corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles range from 2-41°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Ba(2), one Mg(1), and two equivalent Nb(2) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Ba(2), two equivalent Mg(1), one Nb(2), and one Nb(3) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ba(2), two equivalent Mg(1), one Nb(1), and one Nb(4) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Ba(2), one Mg(1), and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Nb(2), and one Nb(3) atom. In the sixth O site, O(6) is bonded in a linear geometry to two equivalent Nb(3) atoms. In the seventh O site, O(7) is bonded in a linear geometry to two equivalent Nb(4) atoms. In the eighth O site, O(8) is bonded to two equivalent Ba(2), two equivalent Mg(1), one Nb(1), and one Nb(2) atom to form distorted edge-sharing OBa2Mg2Nb2 octahedra. In the ninth O site, O(9) is bonded in a linear geometry to one Nb(1) and one Nb(4) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Nb(1), and one Nb(4) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Nb(3), and one Nb(4) atom. In the twelfth O site, O(12) is bonded in a linear geometry to one Nb(2) and one Nb(3) atom. is represented by the CIF file [CIF]
data_Ba2MgNb4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.988
_cell_length_b   6.577
_cell_length_c   10.456
_cell_angle_alpha   89.959
_cell_angle_beta   90.005
_cell_angle_gamma   90.042
_symmetry_Int_Tables_number   1
_cell_volume   274.225
_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
  Ba  Ba0  1  0.000  0.344  0.751  1.0
  Ba  Ba1  1  0.001  0.575  0.250  1.0
  Mg  Mg2  1  0.998  0.057  0.250  1.0
  Nb  Nb3  1  0.500  0.216  0.055  1.0
  Nb  Nb4  1  0.500  0.217  0.445  1.0
  Nb  Nb5  1  0.500  0.783  0.569  1.0
  Nb  Nb6  1  0.500  0.784  0.933  1.0
  O  O7  1  0.000  0.227  0.412  1.0
  O  O8  1  0.500  0.913  0.379  1.0
  O  O9  1  0.500  0.912  0.121  1.0
  O  O10  1  0.000  0.226  0.088  1.0
  O  O11  1  0.500  0.110  0.616  1.0
  O  O12  1  0.000  0.789  0.567  1.0
  O  O13  1  0.000  0.789  0.934  1.0
  O  O14  1  0.500  0.298  0.250  1.0
  O  O15  1  0.500  0.507  0.004  1.0
  O  O16  1  0.500  0.111  0.882  1.0
  O  O17  1  0.500  0.676  0.750  1.0
  O  O18  1  0.500  0.508  0.494  1.0
[/CIF]
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