The material described by MgBi4O9 crystallizes in the monoclinic P2/c space group. Mg(1) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form distorted MgO4 tetrahedra that share corners with four equivalent Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 64-67°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms. In the second Bi site, Bi(2) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form BiO6 octahedra that share  a cornercorner with one Bi(2)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, and  an edgeedge with one Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted tetrahedral geometry to two equivalent Bi(1) and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Bi(1) and two equivalent Bi(2) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgBi4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.738
_cell_length_b   8.244
_cell_length_c   11.397
_cell_angle_alpha   51.167
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   419.954
_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
  Mg  Mg0  1  0.288  0.000  0.750  1.0
  Mg  Mg1  1  0.712  0.000  0.250  1.0
  Bi  Bi2  1  0.774  0.620  0.857  1.0
  Bi  Bi3  1  0.315  0.207  0.936  1.0
  Bi  Bi4  1  0.685  0.207  0.436  1.0
  Bi  Bi5  1  0.226  0.620  0.357  1.0
  Bi  Bi6  1  0.774  0.380  0.643  1.0
  Bi  Bi7  1  0.685  0.793  0.064  1.0
  Bi  Bi8  1  0.226  0.380  0.143  1.0
  Bi  Bi9  1  0.315  0.793  0.564  1.0
  O  O10  1  0.470  0.500  0.750  1.0
  O  O11  1  0.530  0.500  0.250  1.0
  O  O12  1  0.043  0.692  0.497  1.0
  O  O13  1  0.877  0.179  0.293  1.0
  O  O14  1  0.877  0.821  0.207  1.0
  O  O15  1  0.043  0.308  0.003  1.0
  O  O16  1  0.957  0.308  0.503  1.0
  O  O17  1  0.123  0.821  0.707  1.0
  O  O18  1  0.123  0.179  0.793  1.0
  O  O19  1  0.957  0.692  0.997  1.0
  O  O20  1  0.637  0.117  0.880  1.0
  O  O21  1  0.486  0.254  0.576  1.0
  O  O22  1  0.486  0.746  0.924  1.0
  O  O23  1  0.637  0.883  0.620  1.0
  O  O24  1  0.363  0.117  0.380  1.0
  O  O25  1  0.514  0.746  0.424  1.0
  O  O26  1  0.514  0.254  0.076  1.0
  O  O27  1  0.363  0.883  0.120  1.0
[/CIF]
.
The material described by MgBi4O9 crystallizes in the monoclinic P2/c space group. Mg(1) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form distorted MgO4 tetrahedra that share corners with four equivalent Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 64-67°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms. In the second Bi site, Bi(2) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form BiO6 octahedra that share  a cornercorner with one Bi(2)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, and  an edgeedge with one Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles are 48°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted tetrahedral geometry to two equivalent Bi(1) and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Bi(2) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Bi(1), and one Bi(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Bi(1) and two equivalent Bi(2) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgBi4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.738
_cell_length_b   8.244
_cell_length_c   11.397
_cell_angle_alpha   51.167
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   419.954
_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
  Mg  Mg0  1  0.288  0.000  0.750  1.0
  Mg  Mg1  1  0.712  0.000  0.250  1.0
  Bi  Bi2  1  0.774  0.620  0.857  1.0
  Bi  Bi3  1  0.315  0.207  0.936  1.0
  Bi  Bi4  1  0.685  0.207  0.436  1.0
  Bi  Bi5  1  0.226  0.620  0.357  1.0
  Bi  Bi6  1  0.774  0.380  0.643  1.0
  Bi  Bi7  1  0.685  0.793  0.064  1.0
  Bi  Bi8  1  0.226  0.380  0.143  1.0
  Bi  Bi9  1  0.315  0.793  0.564  1.0
  O  O10  1  0.470  0.500  0.750  1.0
  O  O11  1  0.530  0.500  0.250  1.0
  O  O12  1  0.043  0.692  0.497  1.0
  O  O13  1  0.877  0.179  0.293  1.0
  O  O14  1  0.877  0.821  0.207  1.0
  O  O15  1  0.043  0.308  0.003  1.0
  O  O16  1  0.957  0.308  0.503  1.0
  O  O17  1  0.123  0.821  0.707  1.0
  O  O18  1  0.123  0.179  0.793  1.0
  O  O19  1  0.957  0.692  0.997  1.0
  O  O20  1  0.637  0.117  0.880  1.0
  O  O21  1  0.486  0.254  0.576  1.0
  O  O22  1  0.486  0.746  0.924  1.0
  O  O23  1  0.637  0.883  0.620  1.0
  O  O24  1  0.363  0.117  0.380  1.0
  O  O25  1  0.514  0.746  0.424  1.0
  O  O26  1  0.514  0.254  0.076  1.0
  O  O27  1  0.363  0.883  0.120  1.0
[/CIF]
.