The material structure described by Ba3SrMgNb2O9 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent O(1), two equivalent O(4), four equivalent O(2), and four equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Sr(1)O6 octahedra, and faces with six equivalent Nb(1)O6 octahedra. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one Mg(1), one O(4), two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms. Sr(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form distorted SrO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 12-14°. Mg(1) is bonded in a distorted square co-planar geometry to two equivalent Ba(2) and four equivalent O(2) atoms. Nb(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with three equivalent Sr(1)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, and faces with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-14°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), one Sr(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ba(1), two equivalent Ba(2), one Sr(1), one Mg(1), and one Nb(1) atom. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Nb(1) atoms to form a mixture of distorted face and corner-sharing OBa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the fourth O site, O(4) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Nb(1) atoms to form a mixture of distorted face and corner-sharing OBa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-59°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3SrMgNb2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.085
_cell_length_b   6.263
_cell_length_c   8.093
_cell_angle_alpha   90.003
_cell_angle_beta   85.110
_cell_angle_gamma   120.970
_symmetry_Int_Tables_number   1
_cell_volume   263.154
_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  0.000  0.000  1.0
  Ba  Ba1  1  0.386  0.693  0.757  1.0
  Ba  Ba2  1  0.614  0.307  0.243  1.0
  Sr  Sr3  1  0.000  0.000  0.500  1.0
  Mg  Mg4  1  0.000  0.500  0.500  1.0
  Nb  Nb5  1  0.334  0.667  0.163  1.0
  Nb  Nb6  1  0.666  0.333  0.837  1.0
  O  O7  1  0.638  0.819  0.279  1.0
  O  O8  1  0.133  0.778  0.318  1.0
  O  O9  1  0.133  0.355  0.318  1.0
  O  O10  1  0.362  0.181  0.721  1.0
  O  O11  1  0.867  0.222  0.682  1.0
  O  O12  1  0.867  0.645  0.682  1.0
  O  O13  1  0.500  0.500  0.000  1.0
  O  O14  1  0.500  0.000  0.000  1.0
  O  O15  1  0.000  0.500  0.000  1.0
[/CIF]
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The material structure described by Ba3SrMgNb2O9 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent O(1), two equivalent O(4), four equivalent O(2), and four equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Sr(1)O6 octahedra, and faces with six equivalent Nb(1)O6 octahedra. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one Mg(1), one O(4), two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms. Sr(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form distorted SrO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 12-14°. Mg(1) is bonded in a distorted square co-planar geometry to two equivalent Ba(2) and four equivalent O(2) atoms. Nb(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with three equivalent Sr(1)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, and faces with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-14°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), one Sr(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ba(1), two equivalent Ba(2), one Sr(1), one Mg(1), and one Nb(1) atom. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Nb(1) atoms to form a mixture of distorted face and corner-sharing OBa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the fourth O site, O(4) is bonded to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Nb(1) atoms to form a mixture of distorted face and corner-sharing OBa4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-59°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3SrMgNb2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.085
_cell_length_b   6.263
_cell_length_c   8.093
_cell_angle_alpha   90.003
_cell_angle_beta   85.110
_cell_angle_gamma   120.970
_symmetry_Int_Tables_number   1
_cell_volume   263.154
_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  0.000  0.000  1.0
  Ba  Ba1  1  0.386  0.693  0.757  1.0
  Ba  Ba2  1  0.614  0.307  0.243  1.0
  Sr  Sr3  1  0.000  0.000  0.500  1.0
  Mg  Mg4  1  0.000  0.500  0.500  1.0
  Nb  Nb5  1  0.334  0.667  0.163  1.0
  Nb  Nb6  1  0.666  0.333  0.837  1.0
  O  O7  1  0.638  0.819  0.279  1.0
  O  O8  1  0.133  0.778  0.318  1.0
  O  O9  1  0.133  0.355  0.318  1.0
  O  O10  1  0.362  0.181  0.721  1.0
  O  O11  1  0.867  0.222  0.682  1.0
  O  O12  1  0.867  0.645  0.682  1.0
  O  O13  1  0.500  0.500  0.000  1.0
  O  O14  1  0.500  0.000  0.000  1.0
  O  O15  1  0.000  0.500  0.000  1.0
[/CIF]
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