The material described by Co2Bi11O20 crystallizes in the triclinic P1 space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(13), one O(2), one O(5), and one O(8) atom to form distorted CoO5 trigonal bipyramids that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid, and  a cornercorner with one Co(2)O4 tetrahedra. In the second Co site, Co(2) is bonded to one O(18), one O(19), one O(2), and one O(7) atom to form CoO4 tetrahedra that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid, and  a cornercorner with one Co(1)O5 trigonal bipyramid. There are eleven inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a distorted rectangular see-saw-like geometry to one O(16), one O(20), one O(3), and one O(4) atom. In the second Bi site, Bi(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(20), one O(5), and one O(6) atom. In the third Bi site, Bi(3) is bonded to one O(11), one O(13), one O(19), one O(3), and one O(6) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. In the fourth Bi site, Bi(4) is bonded in a 5-coordinate geometry to one O(18), one O(3), one O(4), one O(5), and one O(9) atom. In the fifth Bi site, Bi(5) is bonded to one O(10), one O(15), one O(4), one O(7), and one O(8) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. In the sixth Bi site, Bi(6) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(2), one O(6), and one O(9) atom. In the seventh Bi site, Bi(7) is bonded to one O(12), one O(13), one O(14), one O(17), and one O(7) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra,  a cornercorner with one Co(1)O5 trigonal bipyramid, and  an edgeedge with one Bi(10)O5 square pyramid. In the eighth Bi site, Bi(8) is bonded in a 5-coordinate geometry to one O(10), one O(17), one O(18), one O(20), and one O(8) atom. In the ninth Bi site, Bi(9) is bonded to one O(10), one O(14), one O(16), one O(19), and one O(9) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid, and  a cornercorner with one Co(2)O4 tetrahedra. In the tenth Bi site, Bi(10) is bonded to one O(1), one O(12), one O(15), one O(17), and one O(19) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra,  a cornercorner with one Co(1)O5 trigonal bipyramid, and  an edgeedge with one Bi(7)O5 square pyramid. In the eleventh Bi site, Bi(11) is bonded in a 5-coordinate geometry to one O(11), one O(14), one O(15), one O(16), and one O(18) atom. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Co(1), one Bi(10), and one Bi(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Co(1), one Co(2), and one Bi(6) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(3), and one Bi(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(4), and one Bi(5) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Co(1), one Bi(2), and one Bi(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2), one Bi(3), and one Bi(6) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Co(2), one Bi(5), and one Bi(7) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to one Co(1), one Bi(5), and one Bi(8) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Bi(4), one Bi(6), and one Bi(9) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one Bi(5), one Bi(8), and one Bi(9) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Bi(11), one Bi(3), and one Bi(6) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Bi(10), one Bi(6), and one Bi(7) atom. In the thirteenth O site, O(13) is bonded in a trigonal non-coplanar geometry to one Co(1), one Bi(3), and one Bi(7) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Bi(11), one Bi(7), and one Bi(9) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Bi(10), one Bi(11), and one Bi(5) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Bi(1), one Bi(11), and one Bi(9) atom. In the seventeenth O site, O(17) is bonded in a distorted trigonal non-coplanar geometry to one Bi(10), one Bi(7), and one Bi(8) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one Co(2), one Bi(11), one Bi(4), and one Bi(8) atom. In the nineteenth O site, O(19) is bonded in a distorted tetrahedral geometry to one Co(2), one Bi(10), one Bi(3), and one Bi(9) atom. In the twentieth O site, O(20) is bonded in a trigonal planar geometry to one Bi(1), one Bi(2), and one Bi(8) atom. is represented by the CIF file [CIF]
data_Co2Bi11O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.742
_cell_length_b   8.835
_cell_length_c   8.841
_cell_angle_alpha   110.533
_cell_angle_beta   108.701
_cell_angle_gamma   107.958
_symmetry_Int_Tables_number   1
_cell_volume   533.270
_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
  Co  Co0  1  0.805  0.095  0.333  1.0
  Co  Co1  1  0.004  0.018  0.029  1.0
  Bi  Bi2  1  0.499  0.659  0.804  1.0
  Bi  Bi3  1  0.818  0.484  0.649  1.0
  Bi  Bi4  1  0.295  0.152  0.486  1.0
  Bi  Bi5  1  0.136  0.316  0.821  1.0
  Bi  Bi6  1  0.320  0.832  0.132  1.0
  Bi  Bi7  1  0.703  0.193  0.857  1.0
  Bi  Bi8  1  0.860  0.715  0.198  1.0
  Bi  Bi9  1  0.651  0.797  0.505  1.0
  Bi  Bi10  1  0.149  0.485  0.294  1.0
  Bi  Bi11  1  0.504  0.304  0.161  1.0
  Bi  Bi12  1  0.188  0.862  0.694  1.0
  O  O13  1  0.667  0.259  0.359  1.0
  O  O14  1  0.829  0.059  0.083  1.0
  O  O15  1  0.270  0.386  0.622  1.0
  O  O16  1  0.229  0.611  0.873  1.0
  O  O17  1  0.885  0.234  0.600  1.0
  O  O18  1  0.638  0.356  0.731  1.0
  O  O19  1  0.013  0.812  0.019  1.0
  O  O20  1  0.617  0.874  0.231  1.0
  O  O21  1  0.998  0.391  0.992  1.0
  O  O22  1  0.375  0.607  0.257  1.0
  O  O23  1  0.350  0.123  0.741  1.0
  O  O24  1  0.733  0.380  0.101  1.0
  O  O25  1  0.999  0.015  0.403  1.0
  O  O26  1  0.119  0.744  0.357  1.0
  O  O27  1  0.382  0.996  0.995  1.0
  O  O28  1  0.380  0.761  0.641  1.0
  O  O29  1  0.770  0.649  0.389  1.0
  O  O30  1  0.978  0.012  0.815  1.0
  O  O31  1  0.221  0.215  0.219  1.0
  O  O32  1  0.613  0.604  0.610  1.0
[/CIF]
.
The material described by Co2Bi11O20 crystallizes in the triclinic P1 space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(13), one O(2), one O(5), and one O(8) atom to form distorted CoO5 trigonal bipyramids that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid, and  a cornercorner with one Co(2)O4 tetrahedra. In the second Co site, Co(2) is bonded to one O(18), one O(19), one O(2), and one O(7) atom to form CoO4 tetrahedra that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid, and  a cornercorner with one Co(1)O5 trigonal bipyramid. There are eleven inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a distorted rectangular see-saw-like geometry to one O(16), one O(20), one O(3), and one O(4) atom. In the second Bi site, Bi(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(20), one O(5), and one O(6) atom. In the third Bi site, Bi(3) is bonded to one O(11), one O(13), one O(19), one O(3), and one O(6) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. In the fourth Bi site, Bi(4) is bonded in a 5-coordinate geometry to one O(18), one O(3), one O(4), one O(5), and one O(9) atom. In the fifth Bi site, Bi(5) is bonded to one O(10), one O(15), one O(4), one O(7), and one O(8) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra, and  a cornercorner with one Co(1)O5 trigonal bipyramid. In the sixth Bi site, Bi(6) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(2), one O(6), and one O(9) atom. In the seventh Bi site, Bi(7) is bonded to one O(12), one O(13), one O(14), one O(17), and one O(7) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra,  a cornercorner with one Co(1)O5 trigonal bipyramid, and  an edgeedge with one Bi(10)O5 square pyramid. In the eighth Bi site, Bi(8) is bonded in a 5-coordinate geometry to one O(10), one O(17), one O(18), one O(20), and one O(8) atom. In the ninth Bi site, Bi(9) is bonded to one O(10), one O(14), one O(16), one O(19), and one O(9) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(10)O5 square pyramid,  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(7)O5 square pyramid, and  a cornercorner with one Co(2)O4 tetrahedra. In the tenth Bi site, Bi(10) is bonded to one O(1), one O(12), one O(15), one O(17), and one O(19) atom to form distorted BiO5 square pyramids that share  a cornercorner with one Bi(3)O5 square pyramid,  a cornercorner with one Bi(5)O5 square pyramid,  a cornercorner with one Bi(9)O5 square pyramid,  a cornercorner with one Co(2)O4 tetrahedra,  a cornercorner with one Co(1)O5 trigonal bipyramid, and  an edgeedge with one Bi(7)O5 square pyramid. In the eleventh Bi site, Bi(11) is bonded in a 5-coordinate geometry to one O(11), one O(14), one O(15), one O(16), and one O(18) atom. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Co(1), one Bi(10), and one Bi(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Co(1), one Co(2), and one Bi(6) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(3), and one Bi(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Bi(1), one Bi(4), and one Bi(5) atom. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Co(1), one Bi(2), and one Bi(4) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2), one Bi(3), and one Bi(6) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Co(2), one Bi(5), and one Bi(7) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to one Co(1), one Bi(5), and one Bi(8) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Bi(4), one Bi(6), and one Bi(9) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one Bi(5), one Bi(8), and one Bi(9) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Bi(11), one Bi(3), and one Bi(6) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Bi(10), one Bi(6), and one Bi(7) atom. In the thirteenth O site, O(13) is bonded in a trigonal non-coplanar geometry to one Co(1), one Bi(3), and one Bi(7) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Bi(11), one Bi(7), and one Bi(9) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Bi(10), one Bi(11), and one Bi(5) atom. In the sixteenth O site, O(16) is bonded in a 3-coordinate geometry to one Bi(1), one Bi(11), and one Bi(9) atom. In the seventeenth O site, O(17) is bonded in a distorted trigonal non-coplanar geometry to one Bi(10), one Bi(7), and one Bi(8) atom. In the eighteenth O site, O(18) is bonded in a distorted single-bond geometry to one Co(2), one Bi(11), one Bi(4), and one Bi(8) atom. In the nineteenth O site, O(19) is bonded in a distorted tetrahedral geometry to one Co(2), one Bi(10), one Bi(3), and one Bi(9) atom. In the twentieth O site, O(20) is bonded in a trigonal planar geometry to one Bi(1), one Bi(2), and one Bi(8) atom. is represented by the CIF file [CIF]
data_Co2Bi11O20
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.742
_cell_length_b   8.835
_cell_length_c   8.841
_cell_angle_alpha   110.533
_cell_angle_beta   108.701
_cell_angle_gamma   107.958
_symmetry_Int_Tables_number   1
_cell_volume   533.270
_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
  Co  Co0  1  0.805  0.095  0.333  1.0
  Co  Co1  1  0.004  0.018  0.029  1.0
  Bi  Bi2  1  0.499  0.659  0.804  1.0
  Bi  Bi3  1  0.818  0.484  0.649  1.0
  Bi  Bi4  1  0.295  0.152  0.486  1.0
  Bi  Bi5  1  0.136  0.316  0.821  1.0
  Bi  Bi6  1  0.320  0.832  0.132  1.0
  Bi  Bi7  1  0.703  0.193  0.857  1.0
  Bi  Bi8  1  0.860  0.715  0.198  1.0
  Bi  Bi9  1  0.651  0.797  0.505  1.0
  Bi  Bi10  1  0.149  0.485  0.294  1.0
  Bi  Bi11  1  0.504  0.304  0.161  1.0
  Bi  Bi12  1  0.188  0.862  0.694  1.0
  O  O13  1  0.667  0.259  0.359  1.0
  O  O14  1  0.829  0.059  0.083  1.0
  O  O15  1  0.270  0.386  0.622  1.0
  O  O16  1  0.229  0.611  0.873  1.0
  O  O17  1  0.885  0.234  0.600  1.0
  O  O18  1  0.638  0.356  0.731  1.0
  O  O19  1  0.013  0.812  0.019  1.0
  O  O20  1  0.617  0.874  0.231  1.0
  O  O21  1  0.998  0.391  0.992  1.0
  O  O22  1  0.375  0.607  0.257  1.0
  O  O23  1  0.350  0.123  0.741  1.0
  O  O24  1  0.733  0.380  0.101  1.0
  O  O25  1  0.999  0.015  0.403  1.0
  O  O26  1  0.119  0.744  0.357  1.0
  O  O27  1  0.382  0.996  0.995  1.0
  O  O28  1  0.380  0.761  0.641  1.0
  O  O29  1  0.770  0.649  0.389  1.0
  O  O30  1  0.978  0.012  0.815  1.0
  O  O31  1  0.221  0.215  0.219  1.0
  O  O32  1  0.613  0.604  0.610  1.0
[/CIF]
.