The material described by MgZn2(Bi2O5)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Zn(1)O6 octahedra, corners with four equivalent Bi(1)O6 octahedra, corners with two equivalent Bi(2)O5 trigonal bipyramids,  an edgeedge with one Zn(1)O6 octahedra, edges with two equivalent Bi(1)O6 octahedra, and  a faceface with one Zn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-78°. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted ZnO6 octahedra that share corners with two equivalent Zn(1)O6 octahedra, corners with two equivalent Bi(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with two equivalent Bi(2)O5 trigonal bipyramids, edges with four equivalent Bi(1)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  a faceface with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 1-28°. In the second Zn site, Zn(2) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(3), and two equivalent O(6) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form distorted BiO6 octahedra that share  a cornercorner with one Zn(1)O6 octahedra, corners with three equivalent Bi(1)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent Bi(2)O5 trigonal bipyramids, edges with two equivalent Zn(1)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Bi(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 28-74°. In the second Bi site, Bi(2) is bonded to one O(1), one O(5), one O(6), and two equivalent O(3) atoms to form BiO5 trigonal bipyramids that share  a cornercorner with one Zn(1)O6 octahedra, corners with two equivalent Bi(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with three equivalent Bi(2)O5 trigonal bipyramids, and  an edgeedge with one Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 71-84°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Zn(2) and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded to one Mg(1), two equivalent Zn(1), and two equivalent Bi(1) atoms to form OMgZn2Bi2 trigonal bipyramids that share corners with two equivalent O(2)MgZn2Bi2 trigonal bipyramids, corners with two equivalent O(4)MgZnBi2 trigonal pyramids, and edges with four equivalent O(4)MgZnBi2 trigonal pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Zn(2), one Bi(1), and two equivalent Bi(2) atoms. In the fourth O site, O(4) is bonded to one Mg(1), one Zn(1), and two equivalent Bi(1) atoms to form distorted OMgZnBi2 trigonal pyramids that share  a cornercorner with one O(2)MgZn2Bi2 trigonal bipyramid, corners with two equivalent O(4)MgZnBi2 trigonal pyramids, edges with two equivalent O(2)MgZn2Bi2 trigonal bipyramids, and  an edgeedge with one O(4)MgZnBi2 trigonal pyramid. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to one Mg(1), one Zn(1), one Bi(1), and one Bi(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Zn(2), one Bi(1), and one Bi(2) atom. is represented by the CIF file [CIF]
data_MgZn2(Bi2O5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.487
_cell_length_b   5.738
_cell_length_c   11.070
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   112.296
_symmetry_Int_Tables_number   1
_cell_volume   263.679
_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  0.573  0.968  0.750  1.0
  Zn  Zn1  1  0.829  0.593  0.750  1.0
  Zn  Zn2  1  0.225  0.379  0.250  1.0
  Bi  Bi3  1  0.165  0.306  0.572  1.0
  Bi  Bi4  1  0.850  0.735  0.428  1.0
  Bi  Bi5  1  0.850  0.735  0.072  1.0
  Bi  Bi6  1  0.165  0.306  0.928  1.0
  O  O7  1  0.728  0.543  0.250  1.0
  O  O8  1  0.291  0.588  0.750  1.0
  O  O9  1  0.291  0.630  0.078  1.0
  O  O10  1  0.657  0.287  0.876  1.0
  O  O11  1  0.657  0.287  0.624  1.0
  O  O12  1  0.291  0.630  0.422  1.0
  O  O13  1  0.906  0.894  0.628  1.0
  O  O14  1  0.066  0.123  0.386  1.0
  O  O15  1  0.906  0.894  0.872  1.0
  O  O16  1  0.066  0.123  0.114  1.0
[/CIF]
.
The material described by MgZn2(Bi2O5)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Zn(1)O6 octahedra, corners with four equivalent Bi(1)O6 octahedra, corners with two equivalent Bi(2)O5 trigonal bipyramids,  an edgeedge with one Zn(1)O6 octahedra, edges with two equivalent Bi(1)O6 octahedra, and  a faceface with one Zn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-78°. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms to form distorted ZnO6 octahedra that share corners with two equivalent Zn(1)O6 octahedra, corners with two equivalent Bi(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with two equivalent Bi(2)O5 trigonal bipyramids, edges with four equivalent Bi(1)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  a faceface with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 1-28°. In the second Zn site, Zn(2) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(3), and two equivalent O(6) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form distorted BiO6 octahedra that share  a cornercorner with one Zn(1)O6 octahedra, corners with three equivalent Bi(1)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent Bi(2)O5 trigonal bipyramids, edges with two equivalent Zn(1)O6 octahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Bi(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 28-74°. In the second Bi site, Bi(2) is bonded to one O(1), one O(5), one O(6), and two equivalent O(3) atoms to form BiO5 trigonal bipyramids that share  a cornercorner with one Zn(1)O6 octahedra, corners with two equivalent Bi(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with three equivalent Bi(2)O5 trigonal bipyramids, and  an edgeedge with one Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 71-84°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to one Zn(2) and two equivalent Bi(2) atoms. In the second O site, O(2) is bonded to one Mg(1), two equivalent Zn(1), and two equivalent Bi(1) atoms to form OMgZn2Bi2 trigonal bipyramids that share corners with two equivalent O(2)MgZn2Bi2 trigonal bipyramids, corners with two equivalent O(4)MgZnBi2 trigonal pyramids, and edges with four equivalent O(4)MgZnBi2 trigonal pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Zn(2), one Bi(1), and two equivalent Bi(2) atoms. In the fourth O site, O(4) is bonded to one Mg(1), one Zn(1), and two equivalent Bi(1) atoms to form distorted OMgZnBi2 trigonal pyramids that share  a cornercorner with one O(2)MgZn2Bi2 trigonal bipyramid, corners with two equivalent O(4)MgZnBi2 trigonal pyramids, edges with two equivalent O(2)MgZn2Bi2 trigonal bipyramids, and  an edgeedge with one O(4)MgZnBi2 trigonal pyramid. In the fifth O site, O(5) is bonded in a distorted see-saw-like geometry to one Mg(1), one Zn(1), one Bi(1), and one Bi(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Zn(2), one Bi(1), and one Bi(2) atom. is represented by the CIF file [CIF]
data_MgZn2(Bi2O5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.487
_cell_length_b   5.738
_cell_length_c   11.070
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   112.296
_symmetry_Int_Tables_number   1
_cell_volume   263.679
_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  0.573  0.968  0.750  1.0
  Zn  Zn1  1  0.829  0.593  0.750  1.0
  Zn  Zn2  1  0.225  0.379  0.250  1.0
  Bi  Bi3  1  0.165  0.306  0.572  1.0
  Bi  Bi4  1  0.850  0.735  0.428  1.0
  Bi  Bi5  1  0.850  0.735  0.072  1.0
  Bi  Bi6  1  0.165  0.306  0.928  1.0
  O  O7  1  0.728  0.543  0.250  1.0
  O  O8  1  0.291  0.588  0.750  1.0
  O  O9  1  0.291  0.630  0.078  1.0
  O  O10  1  0.657  0.287  0.876  1.0
  O  O11  1  0.657  0.287  0.624  1.0
  O  O12  1  0.291  0.630  0.422  1.0
  O  O13  1  0.906  0.894  0.628  1.0
  O  O14  1  0.066  0.123  0.386  1.0
  O  O15  1  0.906  0.894  0.872  1.0
  O  O16  1  0.066  0.123  0.114  1.0
[/CIF]
.