The material structure described by Bi4O5 crystallizes in the monoclinic Cc space group. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a T-shaped geometry to one O(1), one O(3), and one O(4) atom. In the second Bi site, Bi(2) is bonded to one O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(4)O4 trigonal pyramid, edges with two equivalent Bi(2)O5 square pyramids, and edges with two equivalent Bi(3)O5 square pyramids. In the third Bi site, Bi(3) is bonded to one O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(2)O5 square pyramid, corners with three equivalent Bi(4)O4 trigonal pyramids, edges with two equivalent Bi(2)O5 square pyramids, and edges with two equivalent Bi(3)O5 square pyramids. In the fourth Bi site, Bi(4) is bonded to one O(1), one O(5), and two equivalent O(3) atoms to form distorted BiO4 trigonal pyramids that share  a cornercorner with one Bi(2)O5 square pyramid, corners with three equivalent Bi(3)O5 square pyramids, and corners with two equivalent Bi(4)O4 trigonal pyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Bi(1), one Bi(2), one Bi(3), and one Bi(4) atom to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Bi(2) and two equivalent Bi(3) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Bi(1) and two equivalent Bi(4) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Bi(1) and two equivalent Bi(2) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Bi(4) and two equivalent Bi(3) atoms. is represented by the CIF file [CIF]
data_Bi4O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.813
_cell_length_b   7.813
_cell_length_c   5.685
_cell_angle_alpha   83.954
_cell_angle_beta   83.954
_cell_angle_gamma   88.985
_symmetry_Int_Tables_number   1
_cell_volume   343.212
_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  0.199  0.541  0.745  1.0
  Bi  Bi1  1  0.236  0.031  0.759  1.0
  Bi  Bi2  1  0.767  0.962  0.702  1.0
  Bi  Bi3  1  0.712  0.441  0.797  1.0
  Bi  Bi4  1  0.031  0.236  0.259  1.0
  Bi  Bi5  1  0.441  0.712  0.297  1.0
  Bi  Bi6  1  0.541  0.199  0.245  1.0
  Bi  Bi7  1  0.962  0.767  0.202  1.0
  O  O8  1  0.241  0.764  0.000  1.0
  O  O9  1  0.978  0.022  0.970  1.0
  O  O10  1  0.486  0.540  0.644  1.0
  O  O11  1  0.169  0.292  0.556  1.0
  O  O12  1  0.697  0.864  0.361  1.0
  O  O13  1  0.764  0.241  0.500  1.0
  O  O14  1  0.022  0.978  0.470  1.0
  O  O15  1  0.540  0.486  0.144  1.0
  O  O16  1  0.292  0.169  0.056  1.0
  O  O17  1  0.864  0.697  0.861  1.0
[/CIF]
.
The material structure described by Bi4O5 crystallizes in the monoclinic Cc space group. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a T-shaped geometry to one O(1), one O(3), and one O(4) atom. In the second Bi site, Bi(2) is bonded to one O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(4)O4 trigonal pyramid, edges with two equivalent Bi(2)O5 square pyramids, and edges with two equivalent Bi(3)O5 square pyramids. In the third Bi site, Bi(3) is bonded to one O(1), two equivalent O(2), and two equivalent O(5) atoms to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(2)O5 square pyramid, corners with three equivalent Bi(4)O4 trigonal pyramids, edges with two equivalent Bi(2)O5 square pyramids, and edges with two equivalent Bi(3)O5 square pyramids. In the fourth Bi site, Bi(4) is bonded to one O(1), one O(5), and two equivalent O(3) atoms to form distorted BiO4 trigonal pyramids that share  a cornercorner with one Bi(2)O5 square pyramid, corners with three equivalent Bi(3)O5 square pyramids, and corners with two equivalent Bi(4)O4 trigonal pyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Bi(1), one Bi(2), one Bi(3), and one Bi(4) atom to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the second O site, O(2) is bonded to two equivalent Bi(2) and two equivalent Bi(3) atoms to form a mixture of corner and edge-sharing OBi4 tetrahedra. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Bi(1) and two equivalent Bi(4) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Bi(1) and two equivalent Bi(2) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Bi(4) and two equivalent Bi(3) atoms. is represented by the CIF file [CIF]
data_Bi4O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.813
_cell_length_b   7.813
_cell_length_c   5.685
_cell_angle_alpha   83.954
_cell_angle_beta   83.954
_cell_angle_gamma   88.985
_symmetry_Int_Tables_number   1
_cell_volume   343.212
_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  0.199  0.541  0.745  1.0
  Bi  Bi1  1  0.236  0.031  0.759  1.0
  Bi  Bi2  1  0.767  0.962  0.702  1.0
  Bi  Bi3  1  0.712  0.441  0.797  1.0
  Bi  Bi4  1  0.031  0.236  0.259  1.0
  Bi  Bi5  1  0.441  0.712  0.297  1.0
  Bi  Bi6  1  0.541  0.199  0.245  1.0
  Bi  Bi7  1  0.962  0.767  0.202  1.0
  O  O8  1  0.241  0.764  0.000  1.0
  O  O9  1  0.978  0.022  0.970  1.0
  O  O10  1  0.486  0.540  0.644  1.0
  O  O11  1  0.169  0.292  0.556  1.0
  O  O12  1  0.697  0.864  0.361  1.0
  O  O13  1  0.764  0.241  0.500  1.0
  O  O14  1  0.022  0.978  0.470  1.0
  O  O15  1  0.540  0.486  0.144  1.0
  O  O16  1  0.292  0.169  0.056  1.0
  O  O17  1  0.864  0.697  0.861  1.0
[/CIF]
.