The structure described by Sr4MgFe4O11 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(5), one O(7), and one O(9) atom. In the second Sr site, Sr(2) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(4), one O(5), one O(6), and one O(9) atom. Mg(1) is bonded in a distorted square co-planar geometry to one O(11), one O(2), one O(8), and one O(9) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(11), one O(2), one O(5), and one O(6) atom to form distorted corner-sharing FeO5 trigonal bipyramids. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(4), one O(7), and one O(8) atom to form distorted corner-sharing FeO5 trigonal bipyramids. In the third Fe site, Fe(3) is bonded to one O(2), one O(4), one O(5), one O(7), and one O(9) atom to form corner-sharing FeO5 square pyramids. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(3), one O(6), one O(8), and one O(9) atom to form corner-sharing FeO5 trigonal bipyramids. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Mg(1), one Fe(1), and one Fe(3) atom. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Sr(3), and one Fe(4) atom to form distorted corner-sharing OSr3Fe tetrahedra. In the fourth O site, O(4) is bonded to one Sr(2), one Sr(3), one Sr(4), one Fe(2), and one Fe(3) atom to form distorted corner-sharing OSr3Fe2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Fe(1), and one Fe(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(3), one Sr(4), one Fe(1), and one Fe(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Fe(2), and one Fe(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(3), one Mg(1), one Fe(2), and one Fe(4) atom. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(4), one Mg(1), one Fe(3), and one Fe(4) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Sr(4), one Fe(1), and one Fe(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(4), one Mg(1), one Fe(1), and one Fe(2) atom. is represented by the CIF file [CIF]
data_Sr4MgFe4O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.163
_cell_length_b   6.793
_cell_length_c   7.139
_cell_angle_alpha   111.678
_cell_angle_beta   95.943
_cell_angle_gamma   86.590
_symmetry_Int_Tables_number   1
_cell_volume   276.171
_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  0.048  0.775  0.288  1.0
  Sr  Sr1  1  0.898  0.278  0.812  1.0
  Sr  Sr2  1  0.502  0.954  0.968  1.0
  Sr  Sr3  1  0.596  0.500  0.460  1.0
  Mg  Mg4  1  0.240  0.341  0.606  1.0
  Fe  Fe5  1  0.557  0.999  0.466  1.0
  Fe  Fe6  1  0.443  0.473  0.011  1.0
  Fe  Fe7  1  0.999  0.253  0.244  1.0
  Fe  Fe8  1  0.001  0.762  0.755  1.0
  O  O9  1  0.162  0.969  0.715  1.0
  O  O10  1  0.261  0.115  0.335  1.0
  O  O11  1  0.840  0.703  0.942  1.0
  O  O12  1  0.714  0.318  0.105  1.0
  O  O13  1  0.792  0.104  0.368  1.0
  O  O14  1  0.710  0.869  0.644  1.0
  O  O15  1  0.194  0.368  0.099  1.0
  O  O16  1  0.281  0.615  0.843  1.0
  O  O17  1  0.005  0.498  0.496  1.0
  O  O18  1  0.474  0.723  0.257  1.0
  O  O19  1  0.520  0.272  0.707  1.0
[/CIF]
.
The structure described by Sr4MgFe4O11 crystallizes in the triclinic P1 space group. There are four inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(5), one O(7), and one O(9) atom. In the second Sr site, Sr(2) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the third Sr site, Sr(3) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the fourth Sr site, Sr(4) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(4), one O(5), one O(6), and one O(9) atom. Mg(1) is bonded in a distorted square co-planar geometry to one O(11), one O(2), one O(8), and one O(9) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(11), one O(2), one O(5), and one O(6) atom to form distorted corner-sharing FeO5 trigonal bipyramids. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(4), one O(7), and one O(8) atom to form distorted corner-sharing FeO5 trigonal bipyramids. In the third Fe site, Fe(3) is bonded to one O(2), one O(4), one O(5), one O(7), and one O(9) atom to form corner-sharing FeO5 square pyramids. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(3), one O(6), one O(8), and one O(9) atom to form corner-sharing FeO5 trigonal bipyramids. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Mg(1), one Fe(1), and one Fe(3) atom. In the third O site, O(3) is bonded to one Sr(1), one Sr(2), one Sr(3), and one Fe(4) atom to form distorted corner-sharing OSr3Fe tetrahedra. In the fourth O site, O(4) is bonded to one Sr(2), one Sr(3), one Sr(4), one Fe(2), and one Fe(3) atom to form distorted corner-sharing OSr3Fe2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Sr(4), one Fe(1), and one Fe(3) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(3), one Sr(4), one Fe(1), and one Fe(4) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Sr(1), one Sr(2), one Sr(3), one Fe(2), and one Fe(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Sr(3), one Mg(1), one Fe(2), and one Fe(4) atom. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(4), one Mg(1), one Fe(3), and one Fe(4) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Sr(1), one Sr(3), one Sr(4), one Fe(1), and one Fe(2) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Sr(2), one Sr(4), one Mg(1), one Fe(1), and one Fe(2) atom. is represented by the CIF file [CIF]
data_Sr4MgFe4O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.163
_cell_length_b   6.793
_cell_length_c   7.139
_cell_angle_alpha   111.678
_cell_angle_beta   95.943
_cell_angle_gamma   86.590
_symmetry_Int_Tables_number   1
_cell_volume   276.171
_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  0.048  0.775  0.288  1.0
  Sr  Sr1  1  0.898  0.278  0.812  1.0
  Sr  Sr2  1  0.502  0.954  0.968  1.0
  Sr  Sr3  1  0.596  0.500  0.460  1.0
  Mg  Mg4  1  0.240  0.341  0.606  1.0
  Fe  Fe5  1  0.557  0.999  0.466  1.0
  Fe  Fe6  1  0.443  0.473  0.011  1.0
  Fe  Fe7  1  0.999  0.253  0.244  1.0
  Fe  Fe8  1  0.001  0.762  0.755  1.0
  O  O9  1  0.162  0.969  0.715  1.0
  O  O10  1  0.261  0.115  0.335  1.0
  O  O11  1  0.840  0.703  0.942  1.0
  O  O12  1  0.714  0.318  0.105  1.0
  O  O13  1  0.792  0.104  0.368  1.0
  O  O14  1  0.710  0.869  0.644  1.0
  O  O15  1  0.194  0.368  0.099  1.0
  O  O16  1  0.281  0.615  0.843  1.0
  O  O17  1  0.005  0.498  0.496  1.0
  O  O18  1  0.474  0.723  0.257  1.0
  O  O19  1  0.520  0.272  0.707  1.0
[/CIF]
.