The crystal structure described by Bi6Fe2Ti3O18 crystallizes in the monoclinic Cm space group. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(11), one O(8), and four equivalent O(4) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and corners with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-19°. In the second Ti site, Ti(2) is bonded in a 6-coordinate geometry to one O(5), one O(7), and four equivalent O(1) atoms. In the third Ti site, Ti(3) is bonded to one O(6), one O(8), and four equivalent O(2) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 19-21°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(11), and four equivalent O(12) atoms to form FeO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-17°. In the second Fe site, Fe(2) is bonded to one O(10), one O(7), and four equivalent O(3) atoms to form corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 14-15°. There are six inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 3-coordinate geometry to one O(11), two equivalent O(12), and two equivalent O(4) atoms. In the second Bi site, Bi(2) is bonded in a 3-coordinate geometry to one O(10) and two equivalent O(3) atoms. In the third Bi site, Bi(3) is bonded in a distorted pentagonal planar geometry to one O(6) and four equivalent O(9) atoms. In the fourth Bi site, Bi(4) is bonded in a distorted pentagonal planar geometry to one O(5) and four equivalent O(9) atoms. In the fifth Bi site, Bi(5) is bonded in a 5-coordinate geometry to one O(8), two equivalent O(2), and two equivalent O(4) atoms. In the sixth Bi site, Bi(6) is bonded in a 3-coordinate geometry to one O(7) and two equivalent O(1) atoms. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Ti(2) and one Bi(6) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ti(3) and one Bi(5) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Fe(2) and one Bi(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ti(1), one Bi(1), and one Bi(5) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ti(2) and one Bi(4) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Ti(3) and one Bi(3) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ti(2), one Fe(2), and one Bi(6) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(3), and one Bi(5) atom. In the ninth O site, O(9) is bonded to two equivalent Bi(3) and two equivalent Bi(4) atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Bi(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ti(1), one Fe(1), and one Bi(1) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to two equivalent Fe(1) and one Bi(1) atom. is represented by the CIF card [CIF]
data_Ti3Fe2(BiO3)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.000
_cell_length_b   4.000
_cell_length_c   24.669
_cell_angle_alpha   85.683
_cell_angle_beta   85.683
_cell_angle_gamma   88.289
_symmetry_Int_Tables_number   1
_cell_volume   392.453
_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
  Ti  Ti0  1  0.437  0.437  0.166  1.0
  Ti  Ti1  1  0.682  0.682  0.664  1.0
  Ti  Ti2  1  0.349  0.349  0.333  1.0
  Fe  Fe3  1  0.508  0.508  0.001  1.0
  Fe  Fe4  1  0.594  0.594  0.834  1.0
  Bi  Bi5  1  0.041  0.041  0.074  1.0
  Bi  Bi6  1  0.134  0.134  0.908  1.0
  Bi  Bi7  1  0.891  0.891  0.445  1.0
  Bi  Bi8  1  0.333  0.333  0.548  1.0
  Bi  Bi9  1  0.950  0.950  0.252  1.0
  Bi  Bi10  1  0.214  0.214  0.744  1.0
  O  O11  1  0.629  0.147  0.678  1.0
  O  O12  1  0.821  0.306  0.320  1.0
  O  O13  1  0.306  0.821  0.320  1.0
  O  O14  1  0.147  0.629  0.678  1.0
  O  O15  1  0.540  0.072  0.841  1.0
  O  O16  1  0.892  0.376  0.167  1.0
  O  O17  1  0.376  0.892  0.167  1.0
  O  O18  1  0.072  0.540  0.841  1.0
  O  O19  1  0.684  0.684  0.593  1.0
  O  O20  1  0.276  0.276  0.406  1.0
  O  O21  1  0.588  0.588  0.755  1.0
  O  O22  1  0.335  0.335  0.245  1.0
  O  O23  1  0.309  0.811  0.498  1.0
  O  O24  1  0.811  0.309  0.498  1.0
  O  O25  1  0.507  0.507  0.921  1.0
  O  O26  1  0.418  0.418  0.087  1.0
  O  O27  1  0.458  0.987  0.008  1.0
  O  O28  1  0.987  0.458  0.008  1.0
[/CIF]
.
The crystal structure described by Bi6Fe2Ti3O18 crystallizes in the monoclinic Cm space group. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(11), one O(8), and four equivalent O(4) atoms to form distorted TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra,  a cornercorner with one Fe(1)O6 octahedra, and corners with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-19°. In the second Ti site, Ti(2) is bonded in a 6-coordinate geometry to one O(5), one O(7), and four equivalent O(1) atoms. In the third Ti site, Ti(3) is bonded to one O(6), one O(8), and four equivalent O(2) atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 19-21°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(10), one O(11), and four equivalent O(12) atoms to form FeO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Fe(2)O6 octahedra, and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-17°. In the second Fe site, Fe(2) is bonded to one O(10), one O(7), and four equivalent O(3) atoms to form corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 14-15°. There are six inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 3-coordinate geometry to one O(11), two equivalent O(12), and two equivalent O(4) atoms. In the second Bi site, Bi(2) is bonded in a 3-coordinate geometry to one O(10) and two equivalent O(3) atoms. In the third Bi site, Bi(3) is bonded in a distorted pentagonal planar geometry to one O(6) and four equivalent O(9) atoms. In the fourth Bi site, Bi(4) is bonded in a distorted pentagonal planar geometry to one O(5) and four equivalent O(9) atoms. In the fifth Bi site, Bi(5) is bonded in a 5-coordinate geometry to one O(8), two equivalent O(2), and two equivalent O(4) atoms. In the sixth Bi site, Bi(6) is bonded in a 3-coordinate geometry to one O(7) and two equivalent O(1) atoms. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Ti(2) and one Bi(6) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ti(3) and one Bi(5) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Fe(2) and one Bi(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ti(1), one Bi(1), and one Bi(5) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ti(2) and one Bi(4) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Ti(3) and one Bi(3) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ti(2), one Fe(2), and one Bi(6) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(3), and one Bi(5) atom. In the ninth O site, O(9) is bonded to two equivalent Bi(3) and two equivalent Bi(4) atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the tenth O site, O(10) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(2), and one Bi(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Ti(1), one Fe(1), and one Bi(1) atom. In the twelfth O site, O(12) is bonded in a distorted T-shaped geometry to two equivalent Fe(1) and one Bi(1) atom. is represented by the CIF card [CIF]
data_Ti3Fe2(BiO3)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.000
_cell_length_b   4.000
_cell_length_c   24.669
_cell_angle_alpha   85.683
_cell_angle_beta   85.683
_cell_angle_gamma   88.289
_symmetry_Int_Tables_number   1
_cell_volume   392.453
_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
  Ti  Ti0  1  0.437  0.437  0.166  1.0
  Ti  Ti1  1  0.682  0.682  0.664  1.0
  Ti  Ti2  1  0.349  0.349  0.333  1.0
  Fe  Fe3  1  0.508  0.508  0.001  1.0
  Fe  Fe4  1  0.594  0.594  0.834  1.0
  Bi  Bi5  1  0.041  0.041  0.074  1.0
  Bi  Bi6  1  0.134  0.134  0.908  1.0
  Bi  Bi7  1  0.891  0.891  0.445  1.0
  Bi  Bi8  1  0.333  0.333  0.548  1.0
  Bi  Bi9  1  0.950  0.950  0.252  1.0
  Bi  Bi10  1  0.214  0.214  0.744  1.0
  O  O11  1  0.629  0.147  0.678  1.0
  O  O12  1  0.821  0.306  0.320  1.0
  O  O13  1  0.306  0.821  0.320  1.0
  O  O14  1  0.147  0.629  0.678  1.0
  O  O15  1  0.540  0.072  0.841  1.0
  O  O16  1  0.892  0.376  0.167  1.0
  O  O17  1  0.376  0.892  0.167  1.0
  O  O18  1  0.072  0.540  0.841  1.0
  O  O19  1  0.684  0.684  0.593  1.0
  O  O20  1  0.276  0.276  0.406  1.0
  O  O21  1  0.588  0.588  0.755  1.0
  O  O22  1  0.335  0.335  0.245  1.0
  O  O23  1  0.309  0.811  0.498  1.0
  O  O24  1  0.811  0.309  0.498  1.0
  O  O25  1  0.507  0.507  0.921  1.0
  O  O26  1  0.418  0.418  0.087  1.0
  O  O27  1  0.458  0.987  0.008  1.0
  O  O28  1  0.987  0.458  0.008  1.0
[/CIF]
.