The material described by MgNi2(BiO3)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(3), one O(6), and two equivalent O(8) atoms to form distorted MgO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with two equivalent Bi(1)O6 octahedra, and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-54°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(3), one O(6), two equivalent O(1), and two equivalent O(8) atoms to form NiO6 octahedra that share corners with two equivalent Mg(1)O4 tetrahedra, edges with two equivalent Bi(1)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. In the second Ni site, Ni(2) is bonded to one O(7), two equivalent O(4), and two equivalent O(5) atoms to form distorted NiO5 square pyramids that share corners with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom to form BiO6 octahedra that share corners with three equivalent Ni(2)O5 square pyramids,  a cornercorner with one Mg(1)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Bi(1)O6 octahedra. In the second Bi site, Bi(2) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and one O(6) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ni(1), one Bi(1), and one Bi(2) atom. In the second O site, O(2) is bonded in a water-like geometry to two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Ni(1), and two equivalent Bi(2) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ni(2), one Bi(1), and one Bi(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Ni(2), one Bi(1), and one Bi(2) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Ni(1), and two equivalent Bi(2) atoms. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ni(2) and two equivalent Bi(1) atoms. In the eighth O site, O(8) is bonded in a T-shaped geometry to one Mg(1), one Ni(1), and one Bi(1) atom. is represented by the CIF file [CIF]
data_MgNi2(BiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.437
_cell_length_b   5.431
_cell_length_c   9.748
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   101.068
_symmetry_Int_Tables_number   1
_cell_volume   282.474
_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  0.712  0.291  0.000  1.0
  Ni  Ni1  1  0.032  0.968  0.000  1.0
  Ni  Ni2  1  0.561  0.438  0.500  1.0
  Bi  Bi3  1  0.987  0.012  0.335  1.0
  Bi  Bi4  1  0.987  0.012  0.665  1.0
  Bi  Bi5  1  0.424  0.574  0.183  1.0
  Bi  Bi6  1  0.424  0.574  0.817  1.0
  O  O7  1  0.173  0.825  0.172  1.0
  O  O8  1  0.173  0.825  0.828  1.0
  O  O9  1  0.153  0.845  0.500  1.0
  O  O10  1  0.334  0.291  0.000  1.0
  O  O11  1  0.313  0.307  0.346  1.0
  O  O12  1  0.313  0.307  0.654  1.0
  O  O13  1  0.691  0.687  0.345  1.0
  O  O14  1  0.691  0.687  0.655  1.0
  O  O15  1  0.707  0.667  0.000  1.0
  O  O16  1  0.808  0.191  0.500  1.0
  O  O17  1  0.858  0.145  0.152  1.0
  O  O18  1  0.858  0.145  0.848  1.0
[/CIF]
.
The material described by MgNi2(BiO3)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(3), one O(6), and two equivalent O(8) atoms to form distorted MgO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with two equivalent Bi(1)O6 octahedra, and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-54°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(3), one O(6), two equivalent O(1), and two equivalent O(8) atoms to form NiO6 octahedra that share corners with two equivalent Mg(1)O4 tetrahedra, edges with two equivalent Bi(1)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. In the second Ni site, Ni(2) is bonded to one O(7), two equivalent O(4), and two equivalent O(5) atoms to form distorted NiO5 square pyramids that share corners with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 47°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom to form BiO6 octahedra that share corners with three equivalent Ni(2)O5 square pyramids,  a cornercorner with one Mg(1)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Bi(1)O6 octahedra. In the second Bi site, Bi(2) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and one O(6) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ni(1), one Bi(1), and one Bi(2) atom. In the second O site, O(2) is bonded in a water-like geometry to two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Ni(1), and two equivalent Bi(2) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ni(2), one Bi(1), and one Bi(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Ni(2), one Bi(1), and one Bi(2) atom. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Ni(1), and two equivalent Bi(2) atoms. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ni(2) and two equivalent Bi(1) atoms. In the eighth O site, O(8) is bonded in a T-shaped geometry to one Mg(1), one Ni(1), and one Bi(1) atom. is represented by the CIF file [CIF]
data_MgNi2(BiO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.437
_cell_length_b   5.431
_cell_length_c   9.748
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   101.068
_symmetry_Int_Tables_number   1
_cell_volume   282.474
_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  0.712  0.291  0.000  1.0
  Ni  Ni1  1  0.032  0.968  0.000  1.0
  Ni  Ni2  1  0.561  0.438  0.500  1.0
  Bi  Bi3  1  0.987  0.012  0.335  1.0
  Bi  Bi4  1  0.987  0.012  0.665  1.0
  Bi  Bi5  1  0.424  0.574  0.183  1.0
  Bi  Bi6  1  0.424  0.574  0.817  1.0
  O  O7  1  0.173  0.825  0.172  1.0
  O  O8  1  0.173  0.825  0.828  1.0
  O  O9  1  0.153  0.845  0.500  1.0
  O  O10  1  0.334  0.291  0.000  1.0
  O  O11  1  0.313  0.307  0.346  1.0
  O  O12  1  0.313  0.307  0.654  1.0
  O  O13  1  0.691  0.687  0.345  1.0
  O  O14  1  0.691  0.687  0.655  1.0
  O  O15  1  0.707  0.667  0.000  1.0
  O  O16  1  0.808  0.191  0.500  1.0
  O  O17  1  0.858  0.145  0.152  1.0
  O  O18  1  0.858  0.145  0.848  1.0
[/CIF]
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