The compound described by MgBi2O5 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form distorted edge-sharing MgO6 octahedra. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), and two equivalent O(1) atoms. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms to form distorted OMgBi3 trigonal pyramids that share corners with two equivalent O(4)Mg2Bi2 tetrahedra,  an edgeedge with one O(4)Mg2Bi2 tetrahedra, and  an edgeedge with one O(1)MgBi3 trigonal pyramid. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Bi(1), and one Bi(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded to two equivalent Mg(1) and two equivalent Bi(2) atoms to form OMg2Bi2 tetrahedra that share corners with two equivalent O(1)MgBi3 trigonal pyramids, edges with two equivalent O(4)Mg2Bi2 tetrahedra, and  an edgeedge with one O(1)MgBi3 trigonal pyramid. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Bi(1), and one Bi(2) atom. is represented by the CIF card [CIF]
data_MgBi2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.514
_cell_length_b   8.351
_cell_length_c   11.880
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   105.513
_symmetry_Int_Tables_number   1
_cell_volume   527.082
_cell_formula_units_Z   4
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
  Mg  Mg0  1  0.611  0.163  0.918  1.0
  Mg  Mg1  1  0.389  0.837  0.082  1.0
  Mg  Mg2  1  0.889  0.337  0.418  1.0
  Mg  Mg3  1  0.111  0.663  0.582  1.0
  Bi  Bi4  1  0.790  0.957  0.625  1.0
  Bi  Bi5  1  0.210  0.043  0.375  1.0
  Bi  Bi6  1  0.710  0.543  0.125  1.0
  Bi  Bi7  1  0.290  0.457  0.875  1.0
  Bi  Bi8  1  0.094  0.150  0.103  1.0
  Bi  Bi9  1  0.906  0.850  0.897  1.0
  Bi  Bi10  1  0.594  0.650  0.397  1.0
  Bi  Bi11  1  0.406  0.350  0.603  1.0
  O  O12  1  0.494  0.333  0.044  1.0
  O  O13  1  0.978  0.318  0.958  1.0
  O  O14  1  0.501  0.686  0.193  1.0
  O  O15  1  0.761  0.512  0.523  1.0
  O  O16  1  0.779  0.476  0.289  1.0
  O  O17  1  0.279  0.976  0.211  1.0
  O  O18  1  0.478  0.818  0.542  1.0
  O  O19  1  0.522  0.182  0.458  1.0
  O  O20  1  0.239  0.488  0.477  1.0
  O  O21  1  0.006  0.167  0.544  1.0
  O  O22  1  0.221  0.524  0.711  1.0
  O  O23  1  0.506  0.667  0.956  1.0
  O  O24  1  0.994  0.833  0.456  1.0
  O  O25  1  0.721  0.024  0.789  1.0
  O  O26  1  0.739  0.988  0.023  1.0
  O  O27  1  0.261  0.012  0.977  1.0
  O  O28  1  0.499  0.314  0.807  1.0
  O  O29  1  0.022  0.682  0.042  1.0
  O  O30  1  0.999  0.814  0.693  1.0
  O  O31  1  0.001  0.186  0.307  1.0
[/CIF]
.
The compound described by MgBi2O5 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form distorted edge-sharing MgO6 octahedra. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(5), and two equivalent O(1) atoms. In the second Bi site, Bi(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms to form distorted OMgBi3 trigonal pyramids that share corners with two equivalent O(4)Mg2Bi2 tetrahedra,  an edgeedge with one O(4)Mg2Bi2 tetrahedra, and  an edgeedge with one O(1)MgBi3 trigonal pyramid. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Bi(1), and one Bi(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded to two equivalent Mg(1) and two equivalent Bi(2) atoms to form OMg2Bi2 tetrahedra that share corners with two equivalent O(1)MgBi3 trigonal pyramids, edges with two equivalent O(4)Mg2Bi2 tetrahedra, and  an edgeedge with one O(1)MgBi3 trigonal pyramid. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Mg(1), one Bi(1), and one Bi(2) atom. is represented by the CIF card [CIF]
data_MgBi2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.514
_cell_length_b   8.351
_cell_length_c   11.880
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   105.513
_symmetry_Int_Tables_number   1
_cell_volume   527.082
_cell_formula_units_Z   4
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
  Mg  Mg0  1  0.611  0.163  0.918  1.0
  Mg  Mg1  1  0.389  0.837  0.082  1.0
  Mg  Mg2  1  0.889  0.337  0.418  1.0
  Mg  Mg3  1  0.111  0.663  0.582  1.0
  Bi  Bi4  1  0.790  0.957  0.625  1.0
  Bi  Bi5  1  0.210  0.043  0.375  1.0
  Bi  Bi6  1  0.710  0.543  0.125  1.0
  Bi  Bi7  1  0.290  0.457  0.875  1.0
  Bi  Bi8  1  0.094  0.150  0.103  1.0
  Bi  Bi9  1  0.906  0.850  0.897  1.0
  Bi  Bi10  1  0.594  0.650  0.397  1.0
  Bi  Bi11  1  0.406  0.350  0.603  1.0
  O  O12  1  0.494  0.333  0.044  1.0
  O  O13  1  0.978  0.318  0.958  1.0
  O  O14  1  0.501  0.686  0.193  1.0
  O  O15  1  0.761  0.512  0.523  1.0
  O  O16  1  0.779  0.476  0.289  1.0
  O  O17  1  0.279  0.976  0.211  1.0
  O  O18  1  0.478  0.818  0.542  1.0
  O  O19  1  0.522  0.182  0.458  1.0
  O  O20  1  0.239  0.488  0.477  1.0
  O  O21  1  0.006  0.167  0.544  1.0
  O  O22  1  0.221  0.524  0.711  1.0
  O  O23  1  0.506  0.667  0.956  1.0
  O  O24  1  0.994  0.833  0.456  1.0
  O  O25  1  0.721  0.024  0.789  1.0
  O  O26  1  0.739  0.988  0.023  1.0
  O  O27  1  0.261  0.012  0.977  1.0
  O  O28  1  0.499  0.314  0.807  1.0
  O  O29  1  0.022  0.682  0.042  1.0
  O  O30  1  0.999  0.814  0.693  1.0
  O  O31  1  0.001  0.186  0.307  1.0
[/CIF]
.