The material structure described by Bi4O7 crystallizes in the triclinic P-1 space group. There are five inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms to form BiO6 octahedra that share corners with two equivalent Bi(3)O6 octahedra, corners with two equivalent Bi(2)O7 pentagonal bipyramids, and edges with two equivalent Bi(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 47°. In the second Bi site, Bi(2) is bonded to one O(1), one O(4), one O(7), two equivalent O(2), and two equivalent O(3) atoms to form distorted BiO7 pentagonal bipyramids that share  a cornercorner with one Bi(1)O6 octahedra,  a cornercorner with one Bi(3)O6 octahedra,  an edgeedge with one Bi(1)O6 octahedra,  an edgeedge with one Bi(3)O6 octahedra, and edges with two equivalent Bi(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 42-46°. In the third Bi site, Bi(3) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms to form BiO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with two equivalent Bi(2)O7 pentagonal bipyramids, and edges with two equivalent Bi(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 47°. In the fourth Bi site, Bi(4) is bonded in a 5-coordinate geometry to one O(4), one O(5), one O(6), and two equivalent O(1) atoms. In the fifth Bi site, Bi(5) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(7), and two equivalent O(4) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Bi(2), one Bi(5), and two equivalent Bi(4) atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Bi(3) and two equivalent Bi(2) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Bi(1), one Bi(5), and two equivalent Bi(2) atoms. In the fourth O site, O(4) is bonded to one Bi(2), one Bi(4), and two equivalent Bi(5) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Bi(3), one Bi(4), and one Bi(5) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(4), and one Bi(5) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Bi(1), one Bi(2), one Bi(3), and one Bi(5) atom. is represented by the CIF file [CIF]
data_Bi4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.746
_cell_length_b   6.945
_cell_length_c   7.822
_cell_angle_alpha   72.804
_cell_angle_beta   88.992
_cell_angle_gamma   77.301
_symmetry_Int_Tables_number   1
_cell_volume   341.074
_cell_formula_units_Z   2
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
  Bi  Bi0  1  0.000  0.000  0.500  1.0
  Bi  Bi1  1  0.523  0.993  0.743  1.0
  Bi  Bi2  1  0.477  0.007  0.257  1.0
  Bi  Bi3  1  0.000  0.000  0.000  1.0
  Bi  Bi4  1  0.735  0.518  0.117  1.0
  Bi  Bi5  1  0.265  0.482  0.883  1.0
  Bi  Bi6  1  0.271  0.511  0.379  1.0
  Bi  Bi7  1  0.729  0.489  0.621  1.0
  O  O8  1  0.528  0.626  0.813  1.0
  O  O9  1  0.472  0.374  0.187  1.0
  O  O10  1  0.709  0.954  0.059  1.0
  O  O11  1  0.291  0.046  0.941  1.0
  O  O12  1  0.715  0.924  0.479  1.0
  O  O13  1  0.285  0.076  0.521  1.0
  O  O14  1  0.473  0.342  0.635  1.0
  O  O15  1  0.527  0.658  0.365  1.0
  O  O16  1  0.094  0.678  0.036  1.0
  O  O17  1  0.906  0.322  0.964  1.0
  O  O18  1  0.892  0.320  0.371  1.0
  O  O19  1  0.108  0.680  0.629  1.0
  O  O20  1  0.113  0.910  0.273  1.0
  O  O21  1  0.887  0.090  0.727  1.0
[/CIF]
.
The material structure described by Bi4O7 crystallizes in the triclinic P-1 space group. There are five inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms to form BiO6 octahedra that share corners with two equivalent Bi(3)O6 octahedra, corners with two equivalent Bi(2)O7 pentagonal bipyramids, and edges with two equivalent Bi(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 47°. In the second Bi site, Bi(2) is bonded to one O(1), one O(4), one O(7), two equivalent O(2), and two equivalent O(3) atoms to form distorted BiO7 pentagonal bipyramids that share  a cornercorner with one Bi(1)O6 octahedra,  a cornercorner with one Bi(3)O6 octahedra,  an edgeedge with one Bi(1)O6 octahedra,  an edgeedge with one Bi(3)O6 octahedra, and edges with two equivalent Bi(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 42-46°. In the third Bi site, Bi(3) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms to form BiO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with two equivalent Bi(2)O7 pentagonal bipyramids, and edges with two equivalent Bi(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 47°. In the fourth Bi site, Bi(4) is bonded in a 5-coordinate geometry to one O(4), one O(5), one O(6), and two equivalent O(1) atoms. In the fifth Bi site, Bi(5) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(7), and two equivalent O(4) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Bi(2), one Bi(5), and two equivalent Bi(4) atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Bi(3) and two equivalent Bi(2) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Bi(1), one Bi(5), and two equivalent Bi(2) atoms. In the fourth O site, O(4) is bonded to one Bi(2), one Bi(4), and two equivalent Bi(5) atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Bi(3), one Bi(4), and one Bi(5) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(4), and one Bi(5) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Bi(1), one Bi(2), one Bi(3), and one Bi(5) atom. is represented by the CIF file [CIF]
data_Bi4O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.746
_cell_length_b   6.945
_cell_length_c   7.822
_cell_angle_alpha   72.804
_cell_angle_beta   88.992
_cell_angle_gamma   77.301
_symmetry_Int_Tables_number   1
_cell_volume   341.074
_cell_formula_units_Z   2
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
  Bi  Bi0  1  0.000  0.000  0.500  1.0
  Bi  Bi1  1  0.523  0.993  0.743  1.0
  Bi  Bi2  1  0.477  0.007  0.257  1.0
  Bi  Bi3  1  0.000  0.000  0.000  1.0
  Bi  Bi4  1  0.735  0.518  0.117  1.0
  Bi  Bi5  1  0.265  0.482  0.883  1.0
  Bi  Bi6  1  0.271  0.511  0.379  1.0
  Bi  Bi7  1  0.729  0.489  0.621  1.0
  O  O8  1  0.528  0.626  0.813  1.0
  O  O9  1  0.472  0.374  0.187  1.0
  O  O10  1  0.709  0.954  0.059  1.0
  O  O11  1  0.291  0.046  0.941  1.0
  O  O12  1  0.715  0.924  0.479  1.0
  O  O13  1  0.285  0.076  0.521  1.0
  O  O14  1  0.473  0.342  0.635  1.0
  O  O15  1  0.527  0.658  0.365  1.0
  O  O16  1  0.094  0.678  0.036  1.0
  O  O17  1  0.906  0.322  0.964  1.0
  O  O18  1  0.892  0.320  0.371  1.0
  O  O19  1  0.108  0.680  0.629  1.0
  O  O20  1  0.113  0.910  0.273  1.0
  O  O21  1  0.887  0.090  0.727  1.0
[/CIF]
.