The structure described by Ba2Fe3AlO7 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(1), two equivalent O(4), and four equivalent O(6) atoms. In the second Ba site, Ba(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(7) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Fe(2)O4 tetrahedra, corners with two equivalent Al(1)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and  an edgeedge with one Al(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(5), one O(7), and two equivalent O(3) atoms to form distorted FeO4 tetrahedra that share corners with two equivalent Fe(2)O4 tetrahedra, corners with three equivalent Al(1)O4 tetrahedra, and  a cornercorner with one Fe(1)O5 trigonal bipyramid. In the third Fe site, Fe(3) is bonded in a distorted T-shaped geometry to one O(6), one O(7), and two equivalent O(1) atoms. Al(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with three equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Fe(1), and one Al(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ba(2), two equivalent Fe(2), and one Al(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Fe(1), and one Al(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to four equivalent Ba(1), one Fe(1), and one Fe(3) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Ba(2), one Fe(2), and one Fe(3) atom. is represented by the CIF file [CIF]
data_Ba2AlFe3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.770
_cell_length_b   4.748
_cell_length_c   10.867
_cell_angle_alpha   95.724
_cell_angle_beta   88.381
_cell_angle_gamma   91.921
_symmetry_Int_Tables_number   1
_cell_volume   193.356
_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  0.517  0.458  0.812  1.0
  Ba  Ba1  1  0.491  0.559  0.177  1.0
  Al  Al2  1  0.357  0.503  0.501  1.0
  Fe  Fe3  1  0.012  0.921  0.633  1.0
  Fe  Fe4  1  0.973  0.077  0.357  1.0
  Fe  Fe5  1  0.002  0.036  0.994  1.0
  O  O6  1  0.006  0.452  0.996  1.0
  O  O7  1  0.517  0.767  0.620  1.0
  O  O8  1  0.499  0.262  0.377  1.0
  O  O9  1  0.078  0.306  0.606  1.0
  O  O10  1  0.049  0.733  0.444  1.0
  O  O11  1  0.001  0.930  0.815  1.0
  O  O12  1  0.998  0.995  0.169  1.0
[/CIF]
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The structure described by Ba2Fe3AlO7 crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(2), two equivalent O(1), two equivalent O(4), and four equivalent O(6) atoms. In the second Ba site, Ba(2) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(7) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Fe(2)O4 tetrahedra, corners with two equivalent Al(1)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and  an edgeedge with one Al(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(5), one O(7), and two equivalent O(3) atoms to form distorted FeO4 tetrahedra that share corners with two equivalent Fe(2)O4 tetrahedra, corners with three equivalent Al(1)O4 tetrahedra, and  a cornercorner with one Fe(1)O5 trigonal bipyramid. In the third Fe site, Fe(3) is bonded in a distorted T-shaped geometry to one O(6), one O(7), and two equivalent O(1) atoms. Al(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with three equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), and two equivalent Fe(3) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ba(1), two equivalent Fe(1), and one Al(1) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Ba(2), two equivalent Fe(2), and one Al(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Fe(1), and one Al(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one Al(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to four equivalent Ba(1), one Fe(1), and one Fe(3) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Ba(2), one Fe(2), and one Fe(3) atom. is represented by the CIF file [CIF]
data_Ba2AlFe3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.770
_cell_length_b   4.748
_cell_length_c   10.867
_cell_angle_alpha   95.724
_cell_angle_beta   88.381
_cell_angle_gamma   91.921
_symmetry_Int_Tables_number   1
_cell_volume   193.356
_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  0.517  0.458  0.812  1.0
  Ba  Ba1  1  0.491  0.559  0.177  1.0
  Al  Al2  1  0.357  0.503  0.501  1.0
  Fe  Fe3  1  0.012  0.921  0.633  1.0
  Fe  Fe4  1  0.973  0.077  0.357  1.0
  Fe  Fe5  1  0.002  0.036  0.994  1.0
  O  O6  1  0.006  0.452  0.996  1.0
  O  O7  1  0.517  0.767  0.620  1.0
  O  O8  1  0.499  0.262  0.377  1.0
  O  O9  1  0.078  0.306  0.606  1.0
  O  O10  1  0.049  0.733  0.444  1.0
  O  O11  1  0.001  0.930  0.815  1.0
  O  O12  1  0.998  0.995  0.169  1.0
[/CIF]
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