The material described by Sr2MgMnO4 crystallizes in the monoclinic Cm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one O(1) and four equivalent O(2) atoms to form SrO5 square pyramids that share corners with four equivalent Sr(1)O5 square pyramids,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and edges with four equivalent Sr(1)O5 square pyramids. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(2), four equivalent O(1), and four equivalent O(3) atoms. Mg(1) is bonded to one O(1) and four equivalent O(3) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Sr(1)O5 square pyramid and corners with four equivalent Mg(1)O5 trigonal bipyramids. Mn(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), four equivalent Sr(2), and one Mg(1) atom to form distorted OSr5Mg octahedra that share corners with four equivalent O(1)Sr5Mg octahedra, edges with four equivalent O(1)Sr5Mg octahedra, and edges with four equivalent O(2)Sr5Mn octahedra. The corner-sharing octahedral tilt angles are 11°. In the second O site, O(2) is bonded to one Sr(2), four equivalent Sr(1), and one Mn(1) atom to form OSr5Mn octahedra that share corners with four equivalent O(2)Sr5Mn octahedra, edges with four equivalent O(1)Sr5Mg octahedra, and edges with four equivalent O(2)Sr5Mn octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(2), two equivalent Mg(1), and two equivalent Mn(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr2MgMnO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.906
_cell_length_b   3.906
_cell_length_c   9.509
_cell_angle_alpha   114.125
_cell_angle_beta   114.125
_cell_angle_gamma   90.017
_symmetry_Int_Tables_number   1
_cell_volume   118.375
_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  0.682  0.682  0.330  1.0
  Sr  Sr1  1  0.517  0.517  0.666  1.0
  Mg  Mg2  1  0.243  0.243  0.891  1.0
  Mn  Mn3  1  0.922  0.922  0.070  1.0
  O  O4  1  0.986  0.986  0.631  1.0
  O  O5  1  0.197  0.197  0.341  1.0
  O  O6  1  0.810  0.310  0.957  1.0
  O  O7  1  0.310  0.810  0.957  1.0
[/CIF]
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The material described by Sr2MgMnO4 crystallizes in the monoclinic Cm space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to one O(1) and four equivalent O(2) atoms to form SrO5 square pyramids that share corners with four equivalent Sr(1)O5 square pyramids,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and edges with four equivalent Sr(1)O5 square pyramids. In the second Sr site, Sr(2) is bonded in a 9-coordinate geometry to one O(2), four equivalent O(1), and four equivalent O(3) atoms. Mg(1) is bonded to one O(1) and four equivalent O(3) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Sr(1)O5 square pyramid and corners with four equivalent Mg(1)O5 trigonal bipyramids. Mn(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Sr(1), four equivalent Sr(2), and one Mg(1) atom to form distorted OSr5Mg octahedra that share corners with four equivalent O(1)Sr5Mg octahedra, edges with four equivalent O(1)Sr5Mg octahedra, and edges with four equivalent O(2)Sr5Mn octahedra. The corner-sharing octahedral tilt angles are 11°. In the second O site, O(2) is bonded to one Sr(2), four equivalent Sr(1), and one Mn(1) atom to form OSr5Mn octahedra that share corners with four equivalent O(2)Sr5Mn octahedra, edges with four equivalent O(1)Sr5Mg octahedra, and edges with four equivalent O(2)Sr5Mn octahedra. The corner-sharing octahedral tilt angles range from 3-4°. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Sr(2), two equivalent Mg(1), and two equivalent Mn(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr2MgMnO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.906
_cell_length_b   3.906
_cell_length_c   9.509
_cell_angle_alpha   114.125
_cell_angle_beta   114.125
_cell_angle_gamma   90.017
_symmetry_Int_Tables_number   1
_cell_volume   118.375
_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  0.682  0.682  0.330  1.0
  Sr  Sr1  1  0.517  0.517  0.666  1.0
  Mg  Mg2  1  0.243  0.243  0.891  1.0
  Mn  Mn3  1  0.922  0.922  0.070  1.0
  O  O4  1  0.986  0.986  0.631  1.0
  O  O5  1  0.197  0.197  0.341  1.0
  O  O6  1  0.810  0.310  0.957  1.0
  O  O7  1  0.310  0.810  0.957  1.0
[/CIF]
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