The material 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 6-coordinate geometry to one O(12), 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 10-coordinate geometry to one O(10), one O(11), one O(12), one O(13), two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms. Mg(1) is bonded to one O(11), one O(13), one O(3), one O(6), and one O(7) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Fe(8)O4 tetrahedra,  an edgeedge with one Al(1)O6 octahedra, and  an edgeedge with one Fe(7)O4 tetrahedra. 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 FeO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Fe(7)O4 tetrahedra,  a cornercorner with one Fe(8)O4 tetrahedra, corners with two equivalent Fe(5)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the second Fe site, Fe(2) is bonded in a distorted rectangular see-saw-like geometry to one O(11), one O(2), one O(6), and one O(7) atom. In the third Fe site, Fe(3) is bonded in a 4-coordinate geometry to one O(10), one O(13), one O(3), one O(6), and one O(7) atom. In the fourth Fe site, Fe(4) is bonded in a distorted rectangular see-saw-like geometry to one O(14), one O(4), 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,  a cornercorner with one Fe(7)O4 tetrahedra,  a cornercorner with one Fe(8)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. In the sixth Fe site, Fe(6) is bonded in a distorted see-saw-like geometry to one O(10), one O(13), one O(6), and one O(7) atom. In the seventh Fe site, Fe(7) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form FeO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(5)O4 tetrahedra,  a cornercorner with one Al(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. 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(1)O4 tetrahedra,  a cornercorner with one Fe(5)O4 tetrahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 50-60°. 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(1)O4 tetrahedra,  a cornercorner with one Fe(5)O4 tetrahedra, corners with three equivalent Fe(8)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. In the second Al site, Al(2) is bonded to one O(12), one O(14), one O(2), and one O(9) atom to form AlO4 tetrahedra that share  a cornercorner with one Fe(7)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(5)O4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent 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 Fe(2), one Fe(7), and one Al(2) atom to form distorted OBaAlFe2 trigonal pyramids that share  a cornercorner with one O(8)Fe4 tetrahedra and  a cornercorner with one O(7)MgFe4 trigonal bipyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ba(1), one Mg(1), one Fe(3), and one Fe(7) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ba(2), one Fe(4), one Fe(8), and one Al(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Ba(2), one Fe(5), one Fe(8), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Ba(1), one Mg(1), one Fe(2), one Fe(3), one Fe(6), and one Fe(7) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(2), one Fe(3), one Fe(6), and one Fe(8) atom to form distorted corner-sharing OMgFe4 trigonal bipyramids. In the eighth O site, O(8) is bonded to one Fe(1), one Fe(4), one Fe(5), and one Fe(7) atom to form distorted corner-sharing OFe4 tetrahedra. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Ba(1), one Fe(4), one Fe(5), and one Al(2) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Ba(2), one Fe(3), one Fe(6), and one Al(1) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Ba(2), one Mg(1), one Fe(2), and one Al(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Ba(1), one Ba(2), one Fe(1), one Fe(5), and one Al(2) atom. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Ba(2), one Mg(1), one Fe(3), one Fe(6), and one Al(1) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Ba(1), one Fe(1), one Fe(4), and one Al(2) atom. is represented by the CIF file [CIF]
data_Ba2MgAl2(Fe4O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.973
_cell_length_b   6.509
_cell_length_c   10.986
_cell_angle_alpha   91.311
_cell_angle_beta   96.481
_cell_angle_gamma   121.812
_symmetry_Int_Tables_number   1
_cell_volume   358.913
_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  0.723  0.351  0.439  1.0
  Ba  Ba1  1  0.375  0.695  0.973  1.0
  Mg  Mg2  1  0.275  0.104  0.688  1.0
  Al  Al3  1  0.678  0.323  0.903  1.0
  Al  Al4  1  0.433  0.719  0.314  1.0
  Fe  Fe5  1  0.925  0.211  0.183  1.0
  Fe  Fe6  1  0.539  0.892  0.644  1.0
  Fe  Fe7  1  0.134  0.401  0.682  1.0
  Fe  Fe8  1  0.890  0.686  0.174  1.0
  Fe  Fe9  1  0.380  0.177  0.173  1.0
  Fe  Fe10  1  0.831  0.650  0.715  1.0
  Fe  Fe11  1  0.985  0.957  0.446  1.0
  Fe  Fe12  1  0.014  0.020  0.924  1.0
  O  O13  1  0.879  0.220  0.005  1.0
  O  O14  1  0.605  0.859  0.468  1.0
  O  O15  1  0.228  0.283  0.544  1.0
  O  O16  1  0.883  0.676  0.996  1.0
  O  O17  1  0.403  0.216  1.000  1.0
  O  O18  1  0.110  0.770  0.579  1.0
  O  O19  1  0.911  0.991  0.733  1.0
  O  O20  1  0.081  0.022  0.277  1.0
  O  O21  1  0.553  0.535  0.261  1.0
  O  O22  1  0.957  0.462  0.798  1.0
  O  O23  1  0.483  0.015  0.797  1.0
  O  O24  1  0.539  0.974  0.224  1.0
  O  O25  1  0.492  0.445  0.786  1.0
  O  O26  1  0.079  0.535  0.281  1.0
[/CIF]
.
The material 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 6-coordinate geometry to one O(12), 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 10-coordinate geometry to one O(10), one O(11), one O(12), one O(13), two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms. Mg(1) is bonded to one O(11), one O(13), one O(3), one O(6), and one O(7) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Fe(8)O4 tetrahedra,  an edgeedge with one Al(1)O6 octahedra, and  an edgeedge with one Fe(7)O4 tetrahedra. 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 FeO4 tetrahedra that share  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Fe(7)O4 tetrahedra,  a cornercorner with one Fe(8)O4 tetrahedra, corners with two equivalent Fe(5)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the second Fe site, Fe(2) is bonded in a distorted rectangular see-saw-like geometry to one O(11), one O(2), one O(6), and one O(7) atom. In the third Fe site, Fe(3) is bonded in a 4-coordinate geometry to one O(10), one O(13), one O(3), one O(6), and one O(7) atom. In the fourth Fe site, Fe(4) is bonded in a distorted rectangular see-saw-like geometry to one O(14), one O(4), 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,  a cornercorner with one Fe(7)O4 tetrahedra,  a cornercorner with one Fe(8)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. In the sixth Fe site, Fe(6) is bonded in a distorted see-saw-like geometry to one O(10), one O(13), one O(6), and one O(7) atom. In the seventh Fe site, Fe(7) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form FeO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra,  a cornercorner with one Fe(5)O4 tetrahedra,  a cornercorner with one Al(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. 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(1)O4 tetrahedra,  a cornercorner with one Fe(5)O4 tetrahedra, and  a cornercorner with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 50-60°. 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(1)O4 tetrahedra,  a cornercorner with one Fe(5)O4 tetrahedra, corners with three equivalent Fe(8)O4 tetrahedra, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. In the second Al site, Al(2) is bonded to one O(12), one O(14), one O(2), and one O(9) atom to form AlO4 tetrahedra that share  a cornercorner with one Fe(7)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(5)O4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent 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 Fe(2), one Fe(7), and one Al(2) atom to form distorted OBaAlFe2 trigonal pyramids that share  a cornercorner with one O(8)Fe4 tetrahedra and  a cornercorner with one O(7)MgFe4 trigonal bipyramid. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ba(1), one Mg(1), one Fe(3), and one Fe(7) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ba(2), one Fe(4), one Fe(8), and one Al(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Ba(2), one Fe(5), one Fe(8), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Ba(1), one Mg(1), one Fe(2), one Fe(3), one Fe(6), and one Fe(7) atom. In the seventh O site, O(7) is bonded to one Mg(1), one Fe(2), one Fe(3), one Fe(6), and one Fe(8) atom to form distorted corner-sharing OMgFe4 trigonal bipyramids. In the eighth O site, O(8) is bonded to one Fe(1), one Fe(4), one Fe(5), and one Fe(7) atom to form distorted corner-sharing OFe4 tetrahedra. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Ba(1), one Fe(4), one Fe(5), and one Al(2) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Ba(2), one Fe(3), one Fe(6), and one Al(1) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Ba(2), one Mg(1), one Fe(2), and one Al(1) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Ba(1), one Ba(2), one Fe(1), one Fe(5), and one Al(2) atom. In the thirteenth O site, O(13) is bonded in a 5-coordinate geometry to one Ba(2), one Mg(1), one Fe(3), one Fe(6), and one Al(1) atom. In the fourteenth O site, O(14) is bonded in a 4-coordinate geometry to one Ba(1), one Fe(1), one Fe(4), and one Al(2) atom. is represented by the CIF file [CIF]
data_Ba2MgAl2(Fe4O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.973
_cell_length_b   6.509
_cell_length_c   10.986
_cell_angle_alpha   91.311
_cell_angle_beta   96.481
_cell_angle_gamma   121.812
_symmetry_Int_Tables_number   1
_cell_volume   358.913
_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  0.723  0.351  0.439  1.0
  Ba  Ba1  1  0.375  0.695  0.973  1.0
  Mg  Mg2  1  0.275  0.104  0.688  1.0
  Al  Al3  1  0.678  0.323  0.903  1.0
  Al  Al4  1  0.433  0.719  0.314  1.0
  Fe  Fe5  1  0.925  0.211  0.183  1.0
  Fe  Fe6  1  0.539  0.892  0.644  1.0
  Fe  Fe7  1  0.134  0.401  0.682  1.0
  Fe  Fe8  1  0.890  0.686  0.174  1.0
  Fe  Fe9  1  0.380  0.177  0.173  1.0
  Fe  Fe10  1  0.831  0.650  0.715  1.0
  Fe  Fe11  1  0.985  0.957  0.446  1.0
  Fe  Fe12  1  0.014  0.020  0.924  1.0
  O  O13  1  0.879  0.220  0.005  1.0
  O  O14  1  0.605  0.859  0.468  1.0
  O  O15  1  0.228  0.283  0.544  1.0
  O  O16  1  0.883  0.676  0.996  1.0
  O  O17  1  0.403  0.216  1.000  1.0
  O  O18  1  0.110  0.770  0.579  1.0
  O  O19  1  0.911  0.991  0.733  1.0
  O  O20  1  0.081  0.022  0.277  1.0
  O  O21  1  0.553  0.535  0.261  1.0
  O  O22  1  0.957  0.462  0.798  1.0
  O  O23  1  0.483  0.015  0.797  1.0
  O  O24  1  0.539  0.974  0.224  1.0
  O  O25  1  0.492  0.445  0.786  1.0
  O  O26  1  0.079  0.535  0.281  1.0
[/CIF]
.