The material described by MgCrFe(BiO3)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted MgO6 octahedra that share corners with two equivalent Fe(1)O4 trigonal pyramids, edges with three equivalent Bi(2)O6 octahedra, and  an edgeedge with one Fe(1)O4 trigonal pyramid. Cr(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. Fe(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form distorted FeO4 trigonal pyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Bi(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 69-73°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(5) atom. In the second Bi site, Bi(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted BiO6 octahedra that share corners with two equivalent Fe(1)O4 trigonal pyramids, edges with three equivalent Mg(1)O6 octahedra, and  an edgeedge with one Fe(1)O4 trigonal pyramid. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Cr(1), one Bi(1), and one Bi(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Bi(1), and one Bi(2) atom. In the third O site, O(3) is bonded to one Mg(1), one Cr(1), one Fe(1), and one Bi(2) atom to form a mixture of edge and corner-sharing OMgCrFeBi trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Cr(1), one Fe(1), one Bi(1), and one Bi(2) atom to form a mixture of distorted edge and corner-sharing OMgCrFeBi2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Mg(1), one Cr(1), one Bi(1), and one Bi(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Fe(1), and one Bi(2) atom. is represented by the CIF file [CIF]
data_MgCrFe(BiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.334
_cell_length_b   6.645
_cell_length_c   6.826
_cell_angle_alpha   49.946
_cell_angle_beta   50.910
_cell_angle_gamma   50.859
_symmetry_Int_Tables_number   1
_cell_volume   157.907
_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  0.410  0.353  0.357  1.0
  Cr  Cr1  1  0.200  0.195  0.196  1.0
  Fe  Fe2  1  0.822  0.721  0.730  1.0
  Bi  Bi3  1  0.564  0.553  0.568  1.0
  Bi  Bi4  1  0.052  0.012  0.996  1.0
  O  O5  1  0.309  0.542  0.988  1.0
  O  O6  1  0.967  0.419  0.599  1.0
  O  O7  1  0.826  0.391  0.108  1.0
  O  O8  1  0.176  0.810  0.370  1.0
  O  O9  1  0.517  0.994  0.340  1.0
  O  O10  1  0.471  0.087  0.740  1.0
[/CIF]
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The material described by MgCrFe(BiO3)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted MgO6 octahedra that share corners with two equivalent Fe(1)O4 trigonal pyramids, edges with three equivalent Bi(2)O6 octahedra, and  an edgeedge with one Fe(1)O4 trigonal pyramid. Cr(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. Fe(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form distorted FeO4 trigonal pyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Bi(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one Bi(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 69-73°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(5) atom. In the second Bi site, Bi(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted BiO6 octahedra that share corners with two equivalent Fe(1)O4 trigonal pyramids, edges with three equivalent Mg(1)O6 octahedra, and  an edgeedge with one Fe(1)O4 trigonal pyramid. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Cr(1), one Bi(1), and one Bi(2) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Bi(1), and one Bi(2) atom. In the third O site, O(3) is bonded to one Mg(1), one Cr(1), one Fe(1), and one Bi(2) atom to form a mixture of edge and corner-sharing OMgCrFeBi trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Cr(1), one Fe(1), one Bi(1), and one Bi(2) atom to form a mixture of distorted edge and corner-sharing OMgCrFeBi2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Mg(1), one Cr(1), one Bi(1), and one Bi(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Fe(1), and one Bi(2) atom. is represented by the CIF file [CIF]
data_MgCrFe(BiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.334
_cell_length_b   6.645
_cell_length_c   6.826
_cell_angle_alpha   49.946
_cell_angle_beta   50.910
_cell_angle_gamma   50.859
_symmetry_Int_Tables_number   1
_cell_volume   157.907
_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  0.410  0.353  0.357  1.0
  Cr  Cr1  1  0.200  0.195  0.196  1.0
  Fe  Fe2  1  0.822  0.721  0.730  1.0
  Bi  Bi3  1  0.564  0.553  0.568  1.0
  Bi  Bi4  1  0.052  0.012  0.996  1.0
  O  O5  1  0.309  0.542  0.988  1.0
  O  O6  1  0.967  0.419  0.599  1.0
  O  O7  1  0.826  0.391  0.108  1.0
  O  O8  1  0.176  0.810  0.370  1.0
  O  O9  1  0.517  0.994  0.340  1.0
  O  O10  1  0.471  0.087  0.740  1.0
[/CIF]
.