The material described by Sr6Mg(W2O9)2 crystallizes in the trigonal R32 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to two equivalent O(3), two equivalent O(4), four equivalent O(1), and four equivalent O(2) atoms to form distorted SrO12 cuboctahedra that share corners with six equivalent Sr(1)O12 cuboctahedra, corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, faces with two equivalent Sr(1)O12 cuboctahedra, faces with two equivalent W(1)O6 octahedra, and faces with two equivalent W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-22°. In the second Sr site, Sr(2) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. Mg(1) is bonded in a trigonal planar geometry to three equivalent O(3) atoms. There are two inequivalent W sites. In the first W site, W(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted WO6 octahedra that share corners with three equivalent Sr(1)O12 cuboctahedra, faces with three equivalent Sr(1)O12 cuboctahedra, and  a faceface with one W(2)O6 octahedra. In the second W site, W(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form WO6 octahedra that share corners with three equivalent Sr(1)O12 cuboctahedra, faces with three equivalent Sr(1)O12 cuboctahedra,  a faceface with one W(1)O6 octahedra, and  a faceface with one W(2)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Sr(2), two equivalent Sr(1), one W(1), and one W(2) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and one W(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Sr(1), two equivalent Sr(2), and one Mg(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent W(2) atoms. is represented by the CIF card [CIF]
data_Sr6Mg(W2O9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.593
_cell_length_b   7.593
_cell_length_c   7.593
_cell_angle_alpha   83.663
_cell_angle_beta   83.663
_cell_angle_gamma   83.663
_symmetry_Int_Tables_number   1
_cell_volume   430.349
_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
  Sr  Sr0  1  0.250  0.907  0.593  1.0
  Sr  Sr1  1  0.042  0.458  0.750  1.0
  Sr  Sr2  1  0.458  0.750  0.042  1.0
  Sr  Sr3  1  0.593  0.250  0.907  1.0
  Sr  Sr4  1  0.907  0.593  0.250  1.0
  Sr  Sr5  1  0.750  0.042  0.458  1.0
  Mg  Mg6  1  0.750  0.750  0.750  1.0
  W  W7  1  0.971  0.971  0.971  1.0
  W  W8  1  0.344  0.344  0.344  1.0
  W  W9  1  0.156  0.156  0.156  1.0
  W  W10  1  0.529  0.529  0.529  1.0
  O  O11  1  0.109  0.906  0.207  1.0
  O  O12  1  0.086  0.763  0.897  1.0
  O  O13  1  0.558  0.942  0.750  1.0
  O  O14  1  0.293  0.594  0.391  1.0
  O  O15  1  0.096  0.250  0.404  1.0
  O  O16  1  0.250  0.404  0.096  1.0
  O  O17  1  0.414  0.603  0.737  1.0
  O  O18  1  0.603  0.737  0.414  1.0
  O  O19  1  0.763  0.897  0.086  1.0
  O  O20  1  0.207  0.109  0.906  1.0
  O  O21  1  0.391  0.293  0.594  1.0
  O  O22  1  0.942  0.750  0.558  1.0
  O  O23  1  0.594  0.391  0.293  1.0
  O  O24  1  0.750  0.558  0.942  1.0
  O  O25  1  0.737  0.414  0.603  1.0
  O  O26  1  0.404  0.096  0.250  1.0
  O  O27  1  0.906  0.207  0.109  1.0
  O  O28  1  0.897  0.086  0.763  1.0
[/CIF]
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The material described by Sr6Mg(W2O9)2 crystallizes in the trigonal R32 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to two equivalent O(3), two equivalent O(4), four equivalent O(1), and four equivalent O(2) atoms to form distorted SrO12 cuboctahedra that share corners with six equivalent Sr(1)O12 cuboctahedra, corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(2)O6 octahedra, faces with two equivalent Sr(1)O12 cuboctahedra, faces with two equivalent W(1)O6 octahedra, and faces with two equivalent W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 16-22°. In the second Sr site, Sr(2) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. Mg(1) is bonded in a trigonal planar geometry to three equivalent O(3) atoms. There are two inequivalent W sites. In the first W site, W(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted WO6 octahedra that share corners with three equivalent Sr(1)O12 cuboctahedra, faces with three equivalent Sr(1)O12 cuboctahedra, and  a faceface with one W(2)O6 octahedra. In the second W site, W(2) is bonded to three equivalent O(1) and three equivalent O(4) atoms to form WO6 octahedra that share corners with three equivalent Sr(1)O12 cuboctahedra, faces with three equivalent Sr(1)O12 cuboctahedra,  a faceface with one W(1)O6 octahedra, and  a faceface with one W(2)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Sr(2), two equivalent Sr(1), one W(1), and one W(2) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and one W(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Sr(1), two equivalent Sr(2), and one Mg(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent W(2) atoms. is represented by the CIF card [CIF]
data_Sr6Mg(W2O9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.593
_cell_length_b   7.593
_cell_length_c   7.593
_cell_angle_alpha   83.663
_cell_angle_beta   83.663
_cell_angle_gamma   83.663
_symmetry_Int_Tables_number   1
_cell_volume   430.349
_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
  Sr  Sr0  1  0.250  0.907  0.593  1.0
  Sr  Sr1  1  0.042  0.458  0.750  1.0
  Sr  Sr2  1  0.458  0.750  0.042  1.0
  Sr  Sr3  1  0.593  0.250  0.907  1.0
  Sr  Sr4  1  0.907  0.593  0.250  1.0
  Sr  Sr5  1  0.750  0.042  0.458  1.0
  Mg  Mg6  1  0.750  0.750  0.750  1.0
  W  W7  1  0.971  0.971  0.971  1.0
  W  W8  1  0.344  0.344  0.344  1.0
  W  W9  1  0.156  0.156  0.156  1.0
  W  W10  1  0.529  0.529  0.529  1.0
  O  O11  1  0.109  0.906  0.207  1.0
  O  O12  1  0.086  0.763  0.897  1.0
  O  O13  1  0.558  0.942  0.750  1.0
  O  O14  1  0.293  0.594  0.391  1.0
  O  O15  1  0.096  0.250  0.404  1.0
  O  O16  1  0.250  0.404  0.096  1.0
  O  O17  1  0.414  0.603  0.737  1.0
  O  O18  1  0.603  0.737  0.414  1.0
  O  O19  1  0.763  0.897  0.086  1.0
  O  O20  1  0.207  0.109  0.906  1.0
  O  O21  1  0.391  0.293  0.594  1.0
  O  O22  1  0.942  0.750  0.558  1.0
  O  O23  1  0.594  0.391  0.293  1.0
  O  O24  1  0.750  0.558  0.942  1.0
  O  O25  1  0.737  0.414  0.603  1.0
  O  O26  1  0.404  0.096  0.250  1.0
  O  O27  1  0.906  0.207  0.109  1.0
  O  O28  1  0.897  0.086  0.763  1.0
[/CIF]
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