The structure described by MgNbBi3O7 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(5) and three equivalent O(7) atoms to form corner-sharing MgO4 tetrahedra. Nb(1) is bonded in a distorted body-centered cubic geometry to one O(1), one O(6), three equivalent O(2), and three equivalent O(4) atoms. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a linear geometry to one O(3) and one O(7) atom. In the second Bi site, Bi(2) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(3) atoms. In the third Bi site, Bi(3) is bonded in a 7-coordinate geometry to one O(2), three equivalent O(5), and three equivalent O(6) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Nb(1) and three equivalent Bi(2) atoms to form distorted ONbBi3 tetrahedra that share  a cornercorner with one O(6)NbBi3 tetrahedra, corners with three equivalent O(3)Bi4 tetrahedra, corners with three equivalent O(2)Nb3Bi tetrahedra, corners with six equivalent O(1)NbBi3 tetrahedra, edges with three equivalent O(3)Bi4 tetrahedra, and edges with three equivalent O(4)Nb3Bi tetrahedra. In the second O site, O(2) is bonded to three equivalent Nb(1) and one Bi(3) atom to form distorted ONb3Bi tetrahedra that share corners with three equivalent O(5)MgBi3 tetrahedra, corners with three equivalent O(4)Nb3Bi tetrahedra, corners with three equivalent O(1)NbBi3 tetrahedra, corners with six equivalent O(2)Nb3Bi tetrahedra, edges with three equivalent O(4)Nb3Bi tetrahedra, and edges with three equivalent O(6)NbBi3 tetrahedra. In the third O site, O(3) is bonded to one Bi(1) and three equivalent Bi(2) atoms to form distorted OBi4 tetrahedra that share  a cornercorner with one O(7)Mg3Bi tetrahedra, corners with three equivalent O(4)Nb3Bi tetrahedra, corners with three equivalent O(1)NbBi3 tetrahedra, corners with six equivalent O(3)Bi4 tetrahedra, and edges with three equivalent O(1)NbBi3 tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Nb(1) and one Bi(2) atom to form distorted ONb3Bi tetrahedra that share corners with three equivalent O(3)Bi4 tetrahedra, corners with three equivalent O(2)Nb3Bi tetrahedra, corners with three equivalent O(6)NbBi3 tetrahedra, corners with six equivalent O(4)Nb3Bi tetrahedra, edges with three equivalent O(2)Nb3Bi tetrahedra, and edges with three equivalent O(1)NbBi3 tetrahedra. In the fifth O site, O(5) is bonded to one Mg(1) and three equivalent Bi(3) atoms to form distorted OMgBi3 tetrahedra that share corners with three equivalent O(7)Mg3Bi tetrahedra, corners with three equivalent O(2)Nb3Bi tetrahedra, corners with three equivalent O(6)NbBi3 tetrahedra, corners with six equivalent O(5)MgBi3 tetrahedra, and edges with three equivalent O(6)NbBi3 tetrahedra. In the sixth O site, O(6) is bonded to one Nb(1) and three equivalent Bi(3) atoms to form distorted ONbBi3 tetrahedra that share  a cornercorner with one O(1)NbBi3 tetrahedra, corners with three equivalent O(5)MgBi3 tetrahedra, corners with three equivalent O(4)Nb3Bi tetrahedra, corners with six equivalent O(6)NbBi3 tetrahedra, edges with three equivalent O(5)MgBi3 tetrahedra, and edges with three equivalent O(2)Nb3Bi tetrahedra. In the seventh O site, O(7) is bonded to three equivalent Mg(1) and one Bi(1) atom to form distorted OMg3Bi tetrahedra that share  a cornercorner with one O(3)Bi4 tetrahedra, corners with three equivalent O(5)MgBi3 tetrahedra, and corners with six equivalent O(7)Mg3Bi tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNbBi3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.691
_cell_length_b   3.644
_cell_length_c   18.483
_cell_angle_alpha   66.783
_cell_angle_beta   60.617
_cell_angle_gamma   60.445
_symmetry_Int_Tables_number   1
_cell_volume   184.574
_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
  Mg  Mg0  1  0.919  0.288  0.883  1.0
  Nb  Nb1  1  0.963  0.055  0.489  1.0
  Bi  Bi2  1  0.214  0.777  0.065  1.0
  Bi  Bi3  1  0.092  0.887  0.291  1.0
  Bi  Bi4  1  0.978  0.151  0.687  1.0
  O  O5  1  0.298  0.148  0.359  1.0
  O  O6  1  0.297  0.321  0.522  1.0
  O  O7  1  0.907  0.630  0.216  1.0
  O  O8  1  0.778  0.720  0.453  1.0
  O  O9  1  0.172  0.412  0.758  1.0
  O  O10  1  0.772  0.893  0.617  1.0
  O  O11  1  0.529  0.928  0.911  1.0
[/CIF]
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The structure described by MgNbBi3O7 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(5) and three equivalent O(7) atoms to form corner-sharing MgO4 tetrahedra. Nb(1) is bonded in a distorted body-centered cubic geometry to one O(1), one O(6), three equivalent O(2), and three equivalent O(4) atoms. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a linear geometry to one O(3) and one O(7) atom. In the second Bi site, Bi(2) is bonded in a 7-coordinate geometry to one O(4), three equivalent O(1), and three equivalent O(3) atoms. In the third Bi site, Bi(3) is bonded in a 7-coordinate geometry to one O(2), three equivalent O(5), and three equivalent O(6) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Nb(1) and three equivalent Bi(2) atoms to form distorted ONbBi3 tetrahedra that share  a cornercorner with one O(6)NbBi3 tetrahedra, corners with three equivalent O(3)Bi4 tetrahedra, corners with three equivalent O(2)Nb3Bi tetrahedra, corners with six equivalent O(1)NbBi3 tetrahedra, edges with three equivalent O(3)Bi4 tetrahedra, and edges with three equivalent O(4)Nb3Bi tetrahedra. In the second O site, O(2) is bonded to three equivalent Nb(1) and one Bi(3) atom to form distorted ONb3Bi tetrahedra that share corners with three equivalent O(5)MgBi3 tetrahedra, corners with three equivalent O(4)Nb3Bi tetrahedra, corners with three equivalent O(1)NbBi3 tetrahedra, corners with six equivalent O(2)Nb3Bi tetrahedra, edges with three equivalent O(4)Nb3Bi tetrahedra, and edges with three equivalent O(6)NbBi3 tetrahedra. In the third O site, O(3) is bonded to one Bi(1) and three equivalent Bi(2) atoms to form distorted OBi4 tetrahedra that share  a cornercorner with one O(7)Mg3Bi tetrahedra, corners with three equivalent O(4)Nb3Bi tetrahedra, corners with three equivalent O(1)NbBi3 tetrahedra, corners with six equivalent O(3)Bi4 tetrahedra, and edges with three equivalent O(1)NbBi3 tetrahedra. In the fourth O site, O(4) is bonded to three equivalent Nb(1) and one Bi(2) atom to form distorted ONb3Bi tetrahedra that share corners with three equivalent O(3)Bi4 tetrahedra, corners with three equivalent O(2)Nb3Bi tetrahedra, corners with three equivalent O(6)NbBi3 tetrahedra, corners with six equivalent O(4)Nb3Bi tetrahedra, edges with three equivalent O(2)Nb3Bi tetrahedra, and edges with three equivalent O(1)NbBi3 tetrahedra. In the fifth O site, O(5) is bonded to one Mg(1) and three equivalent Bi(3) atoms to form distorted OMgBi3 tetrahedra that share corners with three equivalent O(7)Mg3Bi tetrahedra, corners with three equivalent O(2)Nb3Bi tetrahedra, corners with three equivalent O(6)NbBi3 tetrahedra, corners with six equivalent O(5)MgBi3 tetrahedra, and edges with three equivalent O(6)NbBi3 tetrahedra. In the sixth O site, O(6) is bonded to one Nb(1) and three equivalent Bi(3) atoms to form distorted ONbBi3 tetrahedra that share  a cornercorner with one O(1)NbBi3 tetrahedra, corners with three equivalent O(5)MgBi3 tetrahedra, corners with three equivalent O(4)Nb3Bi tetrahedra, corners with six equivalent O(6)NbBi3 tetrahedra, edges with three equivalent O(5)MgBi3 tetrahedra, and edges with three equivalent O(2)Nb3Bi tetrahedra. In the seventh O site, O(7) is bonded to three equivalent Mg(1) and one Bi(1) atom to form distorted OMg3Bi tetrahedra that share  a cornercorner with one O(3)Bi4 tetrahedra, corners with three equivalent O(5)MgBi3 tetrahedra, and corners with six equivalent O(7)Mg3Bi tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNbBi3O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.691
_cell_length_b   3.644
_cell_length_c   18.483
_cell_angle_alpha   66.783
_cell_angle_beta   60.617
_cell_angle_gamma   60.445
_symmetry_Int_Tables_number   1
_cell_volume   184.574
_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
  Mg  Mg0  1  0.919  0.288  0.883  1.0
  Nb  Nb1  1  0.963  0.055  0.489  1.0
  Bi  Bi2  1  0.214  0.777  0.065  1.0
  Bi  Bi3  1  0.092  0.887  0.291  1.0
  Bi  Bi4  1  0.978  0.151  0.687  1.0
  O  O5  1  0.298  0.148  0.359  1.0
  O  O6  1  0.297  0.321  0.522  1.0
  O  O7  1  0.907  0.630  0.216  1.0
  O  O8  1  0.778  0.720  0.453  1.0
  O  O9  1  0.172  0.412  0.758  1.0
  O  O10  1  0.772  0.893  0.617  1.0
  O  O11  1  0.529  0.928  0.911  1.0
[/CIF]
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