The crystal structure described by Ba2MgAl2(Fe4O7)2 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one O(10), one O(11), one O(13), one O(14), one O(2), one O(3), one O(6), and one O(9) atom. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(13), one O(4), and one O(5) atom. Mg(1) is bonded to one O(14), one O(2), one O(6), one O(8), and one O(9) atom to form distorted MgO5 square pyramids that share corners with two equivalent Fe(5)O4 tetrahedra,  a cornercorner with one Fe(2)O5 trigonal bipyramid, corners with two equivalent Fe(1)O4 trigonal pyramids, and edges with two equivalent Al(2)O6 octahedra. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(12), one O(14), and one O(8) atom to form distorted FeO4 trigonal pyramids that share  a cornercorner with one Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids,  a cornercorner with one Fe(8)O4 tetrahedra, and corners with two equivalent Fe(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-51°. In the second Fe site, Fe(2) is bonded to one O(11), one O(13), one O(2), one O(3), and one O(7) atom to form distorted FeO5 trigonal bipyramids that share corners with two equivalent Al(1)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one Fe(8)O4 tetrahedra, and  an edgeedge with one Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-46°. In the third Fe site, Fe(3) is bonded in a distorted see-saw-like geometry to one O(10), one O(13), one O(3), and one O(7) atom. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(12), one O(4), one O(5), one O(8), and one O(9) atom. In the fifth Fe site, Fe(5) is bonded to one O(12), one O(5), one O(8), and one O(9) atom to form distorted FeO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids,  a cornercorner with one Fe(8)O4 tetrahedra, and corners with two equivalent Fe(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 44-57°. In the sixth Fe site, Fe(6) is bonded in a 5-coordinate geometry to one O(10), one O(11), one O(3), one O(6), and one O(7) atom. In the seventh Fe site, Fe(7) is bonded in a 6-coordinate geometry to one O(14), one O(2), one O(3), one O(6), one O(8), and one O(9) atom. In the eighth Fe site, Fe(8) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form FeO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra,  a cornercorner with one Fe(5)O4 tetrahedra,  a cornercorner with one Fe(2)O5 trigonal bipyramid, and  a cornercorner with one Fe(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 45-65°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(10), one O(11), one O(13), one O(4), and one O(5) atom to form AlO6 octahedra that share  a cornercorner with one Fe(5)O4 tetrahedra, corners with three equivalent Fe(8)O4 tetrahedra, corners with two equivalent Fe(2)O5 trigonal bipyramids, and  a cornercorner with one Fe(1)O4 trigonal pyramid. In the second Al site, Al(2) is bonded to one O(12), one O(14), one O(2), one O(3), one O(6), and one O(9) atom to form AlO6 octahedra that share corners with two equivalent Fe(5)O4 tetrahedra, corners with two equivalent Fe(1)O4 trigonal pyramids, edges with two equivalent Mg(1)O5 square pyramids, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ba(2), one Fe(1), one Fe(8), and one Al(1) atom. In the second O site, O(2) is bonded to one Ba(1), one Mg(1), one Fe(2), one Fe(7), and one Al(2) atom to form distorted OBaMgAlFe2 trigonal bipyramids that share  a cornercorner with one O(7)Fe4 tetrahedra,  a cornercorner with one O(10)Ba2AlFe2 trigonal bipyramid, corners with two equivalent O(13)Ba2AlFe2 trigonal bipyramids,  an edgeedge with one O(11)Ba2AlFe2 trigonal bipyramid, and  an edgeedge with one O(8)MgFe4 trigonal bipyramid. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Ba(1), one Fe(2), one Fe(3), one Fe(6), one Fe(7), and one Al(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ba(2), one Fe(4), one Fe(8), and one Al(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ba(2), one Fe(4), one Fe(5), one Fe(8), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ba(1), one Mg(1), one Fe(6), one Fe(7), and one Al(2) atom. In the seventh O site, O(7) is bonded to one Fe(2), one Fe(3), one Fe(6), and one Fe(8) atom to form OFe4 tetrahedra that share  a cornercorner with one O(2)BaMgAlFe2 trigonal bipyramid, corners with two equivalent O(10)Ba2AlFe2 trigonal bipyramids, corners with two equivalent O(11)Ba2AlFe2 trigonal bipyramids, and corners with two equivalent O(13)Ba2AlFe2 trigonal bipyramids. In the eighth O site, O(8) is bonded to one Mg(1), one Fe(1), one Fe(4), one Fe(5), and one Fe(7) atom to form distorted edge-sharing OMgFe4 trigonal bipyramids. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Ba(1), one Mg(1), one Fe(4), one Fe(5), one Fe(7), and one Al(2) atom. In the tenth O site, O(10) is bonded to one Ba(1), one Ba(2), one Fe(3), one Fe(6), and one Al(1) atom to form distorted OBa2AlFe2 trigonal bipyramids that share corners with two equivalent O(7)Fe4 tetrahedra,  a cornercorner with one O(2)BaMgAlFe2 trigonal bipyramid, edges with two equivalent O(11)Ba2AlFe2 trigonal bipyramids, and edges with two equivalent O(13)Ba2AlFe2 trigonal bipyramids. In the eleventh O site, O(11) is bonded to one Ba(1), one Ba(2), one Fe(2), one Fe(6), and one Al(1) atom to form distorted OBa2AlFe2 trigonal bipyramids that share corners with two equivalent O(7)Fe4 tetrahedra,  an edgeedge with one O(2)BaMgAlFe2 trigonal bipyramid, edges with two equivalent O(10)Ba2AlFe2 trigonal bipyramids, and edges with two equivalent O(13)Ba2AlFe2 trigonal bipyramids. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Ba(2), one Fe(1), one Fe(4), one Fe(5), and one Al(2) atom. In the thirteenth O site, O(13) is bonded to one Ba(1), one Ba(2), one Fe(2), one Fe(3), and one Al(1) atom to form distorted OBa2AlFe2 trigonal bipyramids that share corners with two equivalent O(7)Fe4 tetrahedra, corners with two equivalent O(2)BaMgAlFe2 trigonal bipyramids, edges with two equivalent O(10)Ba2AlFe2 trigonal bipyramids, and edges with two equivalent O(11)Ba2AlFe2 trigonal bipyramids. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Ba(1), one Mg(1), one Fe(1), one Fe(7), and one Al(2) atom. is represented by the CIF card [CIF]
data_Ba2MgAl2(Fe4O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.096
_cell_length_b   6.211
_cell_length_c   10.298
_cell_angle_alpha   96.087
_cell_angle_beta   86.623
_cell_angle_gamma   119.522
_symmetry_Int_Tables_number   1
_cell_volume   337.331
_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
  Ba  Ba0  1  0.628  0.274  0.550  1.0
  Ba  Ba1  1  0.286  0.672  0.964  1.0
  Mg  Mg2  1  0.899  0.699  0.366  1.0
  Al  Al3  1  0.652  0.338  0.881  1.0
  Al  Al4  1  0.381  0.690  0.391  1.0
  Fe  Fe5  1  0.849  0.189  0.181  1.0
  Fe  Fe6  1  0.611  0.788  0.678  1.0
  Fe  Fe7  1  0.144  0.291  0.708  1.0
  Fe  Fe8  1  0.656  0.645  0.147  1.0
  Fe  Fe9  1  0.368  0.118  0.193  1.0
  Fe  Fe10  1  0.145  0.766  0.664  1.0
  Fe  Fe11  1  0.077  0.181  0.421  1.0
  Fe  Fe12  1  0.014  0.020  0.943  1.0
  O  O13  1  0.820  0.215  0.998  1.0
  O  O14  1  0.712  0.883  0.479  1.0
  O  O15  1  0.277  0.490  0.542  1.0
  O  O16  1  0.826  0.659  0.984  1.0
  O  O17  1  0.371  0.243  0.017  1.0
  O  O18  1  0.217  0.875  0.477  1.0
  O  O19  1  0.968  0.952  0.748  1.0
  O  O20  1  0.994  0.963  0.244  1.0
  O  O21  1  0.518  0.468  0.311  1.0
  O  O22  1  0.940  0.457  0.760  1.0
  O  O23  1  0.483  0.005  0.774  1.0
  O  O24  1  0.481  0.868  0.231  1.0
  O  O25  1  0.494  0.460  0.774  1.0
  O  O26  1  0.022  0.449  0.326  1.0
[/CIF]
.
The crystal structure described by Ba2MgAl2(Fe4O7)2 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one O(10), one O(11), one O(13), one O(14), one O(2), one O(3), one O(6), and one O(9) atom. In the second Ba site, Ba(2) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(13), one O(4), and one O(5) atom. Mg(1) is bonded to one O(14), one O(2), one O(6), one O(8), and one O(9) atom to form distorted MgO5 square pyramids that share corners with two equivalent Fe(5)O4 tetrahedra,  a cornercorner with one Fe(2)O5 trigonal bipyramid, corners with two equivalent Fe(1)O4 trigonal pyramids, and edges with two equivalent Al(2)O6 octahedra. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(12), one O(14), and one O(8) atom to form distorted FeO4 trigonal pyramids that share  a cornercorner with one Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids,  a cornercorner with one Fe(8)O4 tetrahedra, and corners with two equivalent Fe(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-51°. In the second Fe site, Fe(2) is bonded to one O(11), one O(13), one O(2), one O(3), and one O(7) atom to form distorted FeO5 trigonal bipyramids that share corners with two equivalent Al(1)O6 octahedra,  a cornercorner with one Mg(1)O5 square pyramid,  a cornercorner with one Fe(8)O4 tetrahedra, and  an edgeedge with one Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-46°. In the third Fe site, Fe(3) is bonded in a distorted see-saw-like geometry to one O(10), one O(13), one O(3), and one O(7) atom. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(12), one O(4), one O(5), one O(8), and one O(9) atom. In the fifth Fe site, Fe(5) is bonded to one O(12), one O(5), one O(8), and one O(9) atom to form distorted FeO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with two equivalent Mg(1)O5 square pyramids,  a cornercorner with one Fe(8)O4 tetrahedra, and corners with two equivalent Fe(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 44-57°. In the sixth Fe site, Fe(6) is bonded in a 5-coordinate geometry to one O(10), one O(11), one O(3), one O(6), and one O(7) atom. In the seventh Fe site, Fe(7) is bonded in a 6-coordinate geometry to one O(14), one O(2), one O(3), one O(6), one O(8), and one O(9) atom. In the eighth Fe site, Fe(8) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form FeO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra,  a cornercorner with one Fe(5)O4 tetrahedra,  a cornercorner with one Fe(2)O5 trigonal bipyramid, and  a cornercorner with one Fe(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 45-65°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(10), one O(11), one O(13), one O(4), and one O(5) atom to form AlO6 octahedra that share  a cornercorner with one Fe(5)O4 tetrahedra, corners with three equivalent Fe(8)O4 tetrahedra, corners with two equivalent Fe(2)O5 trigonal bipyramids, and  a cornercorner with one Fe(1)O4 trigonal pyramid. In the second Al site, Al(2) is bonded to one O(12), one O(14), one O(2), one O(3), one O(6), and one O(9) atom to form AlO6 octahedra that share corners with two equivalent Fe(5)O4 tetrahedra, corners with two equivalent Fe(1)O4 trigonal pyramids, edges with two equivalent Mg(1)O5 square pyramids, and  an edgeedge with one Fe(2)O5 trigonal bipyramid. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ba(2), one Fe(1), one Fe(8), and one Al(1) atom. In the second O site, O(2) is bonded to one Ba(1), one Mg(1), one Fe(2), one Fe(7), and one Al(2) atom to form distorted OBaMgAlFe2 trigonal bipyramids that share  a cornercorner with one O(7)Fe4 tetrahedra,  a cornercorner with one O(10)Ba2AlFe2 trigonal bipyramid, corners with two equivalent O(13)Ba2AlFe2 trigonal bipyramids,  an edgeedge with one O(11)Ba2AlFe2 trigonal bipyramid, and  an edgeedge with one O(8)MgFe4 trigonal bipyramid. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Ba(1), one Fe(2), one Fe(3), one Fe(6), one Fe(7), and one Al(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ba(2), one Fe(4), one Fe(8), and one Al(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ba(2), one Fe(4), one Fe(5), one Fe(8), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ba(1), one Mg(1), one Fe(6), one Fe(7), and one Al(2) atom. In the seventh O site, O(7) is bonded to one Fe(2), one Fe(3), one Fe(6), and one Fe(8) atom to form OFe4 tetrahedra that share  a cornercorner with one O(2)BaMgAlFe2 trigonal bipyramid, corners with two equivalent O(10)Ba2AlFe2 trigonal bipyramids, corners with two equivalent O(11)Ba2AlFe2 trigonal bipyramids, and corners with two equivalent O(13)Ba2AlFe2 trigonal bipyramids. In the eighth O site, O(8) is bonded to one Mg(1), one Fe(1), one Fe(4), one Fe(5), and one Fe(7) atom to form distorted edge-sharing OMgFe4 trigonal bipyramids. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Ba(1), one Mg(1), one Fe(4), one Fe(5), one Fe(7), and one Al(2) atom. In the tenth O site, O(10) is bonded to one Ba(1), one Ba(2), one Fe(3), one Fe(6), and one Al(1) atom to form distorted OBa2AlFe2 trigonal bipyramids that share corners with two equivalent O(7)Fe4 tetrahedra,  a cornercorner with one O(2)BaMgAlFe2 trigonal bipyramid, edges with two equivalent O(11)Ba2AlFe2 trigonal bipyramids, and edges with two equivalent O(13)Ba2AlFe2 trigonal bipyramids. In the eleventh O site, O(11) is bonded to one Ba(1), one Ba(2), one Fe(2), one Fe(6), and one Al(1) atom to form distorted OBa2AlFe2 trigonal bipyramids that share corners with two equivalent O(7)Fe4 tetrahedra,  an edgeedge with one O(2)BaMgAlFe2 trigonal bipyramid, edges with two equivalent O(10)Ba2AlFe2 trigonal bipyramids, and edges with two equivalent O(13)Ba2AlFe2 trigonal bipyramids. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Ba(2), one Fe(1), one Fe(4), one Fe(5), and one Al(2) atom. In the thirteenth O site, O(13) is bonded to one Ba(1), one Ba(2), one Fe(2), one Fe(3), and one Al(1) atom to form distorted OBa2AlFe2 trigonal bipyramids that share corners with two equivalent O(7)Fe4 tetrahedra, corners with two equivalent O(2)BaMgAlFe2 trigonal bipyramids, edges with two equivalent O(10)Ba2AlFe2 trigonal bipyramids, and edges with two equivalent O(11)Ba2AlFe2 trigonal bipyramids. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Ba(1), one Mg(1), one Fe(1), one Fe(7), and one Al(2) atom. is represented by the CIF card [CIF]
data_Ba2MgAl2(Fe4O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.096
_cell_length_b   6.211
_cell_length_c   10.298
_cell_angle_alpha   96.087
_cell_angle_beta   86.623
_cell_angle_gamma   119.522
_symmetry_Int_Tables_number   1
_cell_volume   337.331
_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
  Ba  Ba0  1  0.628  0.274  0.550  1.0
  Ba  Ba1  1  0.286  0.672  0.964  1.0
  Mg  Mg2  1  0.899  0.699  0.366  1.0
  Al  Al3  1  0.652  0.338  0.881  1.0
  Al  Al4  1  0.381  0.690  0.391  1.0
  Fe  Fe5  1  0.849  0.189  0.181  1.0
  Fe  Fe6  1  0.611  0.788  0.678  1.0
  Fe  Fe7  1  0.144  0.291  0.708  1.0
  Fe  Fe8  1  0.656  0.645  0.147  1.0
  Fe  Fe9  1  0.368  0.118  0.193  1.0
  Fe  Fe10  1  0.145  0.766  0.664  1.0
  Fe  Fe11  1  0.077  0.181  0.421  1.0
  Fe  Fe12  1  0.014  0.020  0.943  1.0
  O  O13  1  0.820  0.215  0.998  1.0
  O  O14  1  0.712  0.883  0.479  1.0
  O  O15  1  0.277  0.490  0.542  1.0
  O  O16  1  0.826  0.659  0.984  1.0
  O  O17  1  0.371  0.243  0.017  1.0
  O  O18  1  0.217  0.875  0.477  1.0
  O  O19  1  0.968  0.952  0.748  1.0
  O  O20  1  0.994  0.963  0.244  1.0
  O  O21  1  0.518  0.468  0.311  1.0
  O  O22  1  0.940  0.457  0.760  1.0
  O  O23  1  0.483  0.005  0.774  1.0
  O  O24  1  0.481  0.868  0.231  1.0
  O  O25  1  0.494  0.460  0.774  1.0
  O  O26  1  0.022  0.449  0.326  1.0
[/CIF]
.