The structure described by Sr3MgMn2O7 crystallizes in the tetragonal I-4m2 space group. There are five inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(4) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Mn(1)O5 square pyramids. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. In the third Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. In the fourth Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. In the fifth Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Mg(1) is bonded to four equivalent O(3) atoms to form distorted corner-sharing MgO4 tetrahedra. Mn(1) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MnO5 square pyramids that share corners with five equivalent Mn(1)O5 square pyramids and faces with four equivalent Sr(1)O12 cuboctahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to four equivalent Sr(2) and two equivalent Mg(1) atoms. In the fourth O site, O(4) is bonded to four equivalent Sr(1) and two equivalent Mn(1) atoms to form a mixture of corner and edge-sharing OSr4Mn2 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Sr3MgMn2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.779
_cell_length_b   3.779
_cell_length_c   13.011
_cell_angle_alpha   98.351
_cell_angle_beta   98.351
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   181.847
_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  0.500  0.500  0.000  1.0
  Sr  Sr1  1  0.342  0.342  0.684  1.0
  Sr  Sr2  1  0.658  0.658  0.316  1.0
  Mg  Mg3  1  0.750  0.250  0.500  1.0
  Mn  Mn4  1  0.081  0.081  0.162  1.0
  Mn  Mn5  1  0.919  0.919  0.838  1.0
  O  O6  1  0.906  0.406  0.812  1.0
  O  O7  1  0.408  0.908  0.816  1.0
  O  O8  1  0.092  0.592  0.184  1.0
  O  O9  1  0.594  0.094  0.188  1.0
  O  O10  1  0.791  0.791  0.581  1.0
  O  O11  1  0.000  0.000  0.000  1.0
  O  O12  1  0.209  0.209  0.419  1.0
[/CIF]
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The structure described by Sr3MgMn2O7 crystallizes in the tetragonal I-4m2 space group. There are five inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(4) atoms to form distorted SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Mn(1)O5 square pyramids. In the second Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. In the third Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. In the fourth Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. In the fifth Sr site, Sr(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Mg(1) is bonded to four equivalent O(3) atoms to form distorted corner-sharing MgO4 tetrahedra. Mn(1) is bonded to one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MnO5 square pyramids that share corners with five equivalent Mn(1)O5 square pyramids and faces with four equivalent Sr(1)O12 cuboctahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Sr(1), two equivalent Sr(2), and two equivalent Mn(1) atoms. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to four equivalent Sr(2) and two equivalent Mg(1) atoms. In the fourth O site, O(4) is bonded to four equivalent Sr(1) and two equivalent Mn(1) atoms to form a mixture of corner and edge-sharing OSr4Mn2 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_Sr3MgMn2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.779
_cell_length_b   3.779
_cell_length_c   13.011
_cell_angle_alpha   98.351
_cell_angle_beta   98.351
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   181.847
_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  0.500  0.500  0.000  1.0
  Sr  Sr1  1  0.342  0.342  0.684  1.0
  Sr  Sr2  1  0.658  0.658  0.316  1.0
  Mg  Mg3  1  0.750  0.250  0.500  1.0
  Mn  Mn4  1  0.081  0.081  0.162  1.0
  Mn  Mn5  1  0.919  0.919  0.838  1.0
  O  O6  1  0.906  0.406  0.812  1.0
  O  O7  1  0.408  0.908  0.816  1.0
  O  O8  1  0.092  0.592  0.184  1.0
  O  O9  1  0.594  0.094  0.188  1.0
  O  O10  1  0.791  0.791  0.581  1.0
  O  O11  1  0.000  0.000  0.000  1.0
  O  O12  1  0.209  0.209  0.419  1.0
[/CIF]
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