The structure described by Sr8MgMn6O20 crystallizes in the monoclinic C2/m space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(7), and four equivalent O(3) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(4), and four equivalent O(2) atoms. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(6), and four equivalent O(2) atoms. In the fourth Sr site, Sr(4) is bonded in a 4-coordinate geometry to one O(6), one O(7), two equivalent O(1), and two equivalent O(5) atoms. Mg(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(4), one O(6), two equivalent O(1), and two equivalent O(2) atoms to form a mixture of distorted corner and face-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the second Mn site, Mn(2) is bonded to one O(5), one O(7), two equivalent O(1), and two equivalent O(3) atoms to form a mixture of distorted corner and face-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the third Mn site, Mn(3) is bonded to two equivalent O(6) and four equivalent O(2) atoms to form face-sharing MnO6 octahedra. In the fourth Mn site, Mn(4) is bonded to two equivalent O(5) and four equivalent O(3) atoms to form face-sharing MnO6 octahedra. There are seven inequivalent O sites. In the first O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(2), two equivalent Sr(3), one Mn(1), and one Mn(3) atom. In the second O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Mg(1), one Mn(2), and one Mn(4) atom. In the third O site, O(4) is bonded in a 2-coordinate geometry to one Sr(3), two equivalent Sr(2), and one Mn(1) atom. In the fourth O site, O(5) is bonded in a 5-coordinate geometry to one Sr(1), two equivalent Sr(4), one Mn(2), and one Mn(4) atom. In the fifth O site, O(6) is bonded to one Sr(2), one Sr(4), two equivalent Sr(3), one Mn(1), and one Mn(3) atom to form distorted corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the sixth O site, O(7) is bonded in a 4-coordinate geometry to one Sr(4), two equivalent Sr(1), and one Mn(2) atom. In the seventh O site, O(1) is bonded in a 2-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Mn(1), and one Mn(2) atom. is represented by the CIF card [CIF]
data_Sr8MgMn6O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.556
_cell_length_b   6.783
_cell_length_c   13.976
_cell_angle_alpha   89.602
_cell_angle_beta   90.000
_cell_angle_gamma   114.176
_symmetry_Int_Tables_number   1
_cell_volume   480.432
_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  0.240  0.481  0.110  1.0
  Sr  Sr1  1  0.760  0.519  0.890  1.0
  Sr  Sr2  1  0.743  0.487  0.400  1.0
  Sr  Sr3  1  0.257  0.513  0.600  1.0
  Sr  Sr4  1  0.970  0.940  0.627  1.0
  Sr  Sr5  1  0.030  0.060  0.373  1.0
  Sr  Sr6  1  0.543  0.086  0.197  1.0
  Sr  Sr7  1  0.457  0.914  0.803  1.0
  Mg  Mg8  1  0.500  0.000  0.000  1.0
  Mn  Mn9  1  0.631  0.262  0.647  1.0
  Mn  Mn10  1  0.369  0.738  0.353  1.0
  Mn  Mn11  1  0.877  0.754  0.162  1.0
  Mn  Mn12  1  0.123  0.246  0.838  1.0
  Mn  Mn13  1  0.500  0.000  0.500  1.0
  Mn  Mn14  1  0.000  0.000  0.000  1.0
  O  O15  1  0.360  0.217  0.737  1.0
  O  O16  1  0.143  0.783  0.263  1.0
  O  O17  1  0.640  0.783  0.263  1.0
  O  O18  1  0.857  0.217  0.737  1.0
  O  O19  1  0.160  0.782  0.465  1.0
  O  O20  1  0.378  0.218  0.535  1.0
  O  O21  1  0.347  0.206  0.962  1.0
  O  O22  1  0.141  0.794  0.038  1.0
  O  O23  1  0.840  0.218  0.535  1.0
  O  O24  1  0.622  0.782  0.465  1.0
  O  O25  1  0.653  0.794  0.038  1.0
  O  O26  1  0.859  0.206  0.962  1.0
  O  O27  1  0.778  0.555  0.648  1.0
  O  O28  1  0.222  0.445  0.352  1.0
  O  O29  1  0.040  0.080  0.138  1.0
  O  O30  1  0.960  0.920  0.862  1.0
  O  O31  1  0.457  0.914  0.632  1.0
  O  O32  1  0.728  0.456  0.159  1.0
  O  O33  1  0.272  0.544  0.841  1.0
  O  O34  1  0.543  0.086  0.368  1.0
[/CIF]
.
The structure described by Sr8MgMn6O20 crystallizes in the monoclinic C2/m space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 9-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(7), and four equivalent O(3) atoms. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(6), two equivalent O(1), two equivalent O(4), and four equivalent O(2) atoms. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(6), and four equivalent O(2) atoms. In the fourth Sr site, Sr(4) is bonded in a 4-coordinate geometry to one O(6), one O(7), two equivalent O(1), and two equivalent O(5) atoms. Mg(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(4), one O(6), two equivalent O(1), and two equivalent O(2) atoms to form a mixture of distorted corner and face-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the second Mn site, Mn(2) is bonded to one O(5), one O(7), two equivalent O(1), and two equivalent O(3) atoms to form a mixture of distorted corner and face-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the third Mn site, Mn(3) is bonded to two equivalent O(6) and four equivalent O(2) atoms to form face-sharing MnO6 octahedra. In the fourth Mn site, Mn(4) is bonded to two equivalent O(5) and four equivalent O(3) atoms to form face-sharing MnO6 octahedra. There are seven inequivalent O sites. In the first O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Sr(2), two equivalent Sr(3), one Mn(1), and one Mn(3) atom. In the second O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Mg(1), one Mn(2), and one Mn(4) atom. In the third O site, O(4) is bonded in a 2-coordinate geometry to one Sr(3), two equivalent Sr(2), and one Mn(1) atom. In the fourth O site, O(5) is bonded in a 5-coordinate geometry to one Sr(1), two equivalent Sr(4), one Mn(2), and one Mn(4) atom. In the fifth O site, O(6) is bonded to one Sr(2), one Sr(4), two equivalent Sr(3), one Mn(1), and one Mn(3) atom to form distorted corner-sharing OSr4Mn2 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the sixth O site, O(7) is bonded in a 4-coordinate geometry to one Sr(4), two equivalent Sr(1), and one Mn(2) atom. In the seventh O site, O(1) is bonded in a 2-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Mn(1), and one Mn(2) atom. is represented by the CIF card [CIF]
data_Sr8MgMn6O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.556
_cell_length_b   6.783
_cell_length_c   13.976
_cell_angle_alpha   89.602
_cell_angle_beta   90.000
_cell_angle_gamma   114.176
_symmetry_Int_Tables_number   1
_cell_volume   480.432
_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  0.240  0.481  0.110  1.0
  Sr  Sr1  1  0.760  0.519  0.890  1.0
  Sr  Sr2  1  0.743  0.487  0.400  1.0
  Sr  Sr3  1  0.257  0.513  0.600  1.0
  Sr  Sr4  1  0.970  0.940  0.627  1.0
  Sr  Sr5  1  0.030  0.060  0.373  1.0
  Sr  Sr6  1  0.543  0.086  0.197  1.0
  Sr  Sr7  1  0.457  0.914  0.803  1.0
  Mg  Mg8  1  0.500  0.000  0.000  1.0
  Mn  Mn9  1  0.631  0.262  0.647  1.0
  Mn  Mn10  1  0.369  0.738  0.353  1.0
  Mn  Mn11  1  0.877  0.754  0.162  1.0
  Mn  Mn12  1  0.123  0.246  0.838  1.0
  Mn  Mn13  1  0.500  0.000  0.500  1.0
  Mn  Mn14  1  0.000  0.000  0.000  1.0
  O  O15  1  0.360  0.217  0.737  1.0
  O  O16  1  0.143  0.783  0.263  1.0
  O  O17  1  0.640  0.783  0.263  1.0
  O  O18  1  0.857  0.217  0.737  1.0
  O  O19  1  0.160  0.782  0.465  1.0
  O  O20  1  0.378  0.218  0.535  1.0
  O  O21  1  0.347  0.206  0.962  1.0
  O  O22  1  0.141  0.794  0.038  1.0
  O  O23  1  0.840  0.218  0.535  1.0
  O  O24  1  0.622  0.782  0.465  1.0
  O  O25  1  0.653  0.794  0.038  1.0
  O  O26  1  0.859  0.206  0.962  1.0
  O  O27  1  0.778  0.555  0.648  1.0
  O  O28  1  0.222  0.445  0.352  1.0
  O  O29  1  0.040  0.080  0.138  1.0
  O  O30  1  0.960  0.920  0.862  1.0
  O  O31  1  0.457  0.914  0.632  1.0
  O  O32  1  0.728  0.456  0.159  1.0
  O  O33  1  0.272  0.544  0.841  1.0
  O  O34  1  0.543  0.086  0.368  1.0
[/CIF]
.