The material described by MgCr(CoO3)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-23°. Cr(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-5°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(6) atoms to form CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles are 23°. In the second Co site, Co(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(5) atoms to form distorted CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles are 21°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1) and two equivalent Co(1) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), two equivalent Cr(1), and one Co(2) atom to form OMg2Cr2Co square pyramids that share corners with four equivalent O(4)Mg2Cr2Co square pyramids, corners with three equivalent O(6)MgCo3 trigonal pyramids, edges with two equivalent O(2)Mg2Cr2Co square pyramids, and edges with two equivalent O(4)Mg2Cr2Co square pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), and two equivalent Co(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Cr(1), and one Co(1) atom to form OMg2Cr2Co square pyramids that share corners with four equivalent O(2)Mg2Cr2Co square pyramids, edges with two equivalent O(2)Mg2Cr2Co square pyramids, edges with two equivalent O(4)Mg2Cr2Co square pyramids, and edges with two equivalent O(6)MgCo3 trigonal pyramids. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Cr(1) and two equivalent Co(2) atoms. In the sixth O site, O(6) is bonded to one Mg(1), one Co(2), and two equivalent Co(1) atoms to form OMgCo3 trigonal pyramids that share corners with three equivalent O(2)Mg2Cr2Co square pyramids, corners with two equivalent O(6)MgCo3 trigonal pyramids, and edges with two equivalent O(4)Mg2Cr2Co square pyramids. is represented by the CIF file [CIF]
data_MgCr(CoO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.643
_cell_length_b   2.894
_cell_length_c   5.886
_cell_angle_alpha   89.998
_cell_angle_beta   101.962
_cell_angle_gamma   77.422
_symmetry_Int_Tables_number   1
_cell_volume   107.915
_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  0.329  0.334  0.831  1.0
  Cr  Cr1  1  0.334  0.331  0.332  1.0
  Co  Co2  1  0.980  0.009  0.027  1.0
  Co  Co3  1  0.698  0.650  0.655  1.0
  O  O4  1  0.023  0.487  0.239  1.0
  O  O5  1  0.345  0.826  0.576  1.0
  O  O6  1  0.660  0.169  0.860  1.0
  O  O7  1  0.326  0.835  0.088  1.0
  O  O8  1  0.652  0.173  0.441  1.0
  O  O9  1  0.993  0.502  0.800  1.0
[/CIF]
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The material described by MgCr(CoO3)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(3), one O(6), two equivalent O(2), and two equivalent O(4) atoms to form MgO6 octahedra that share  a cornercorner with one Co(1)O6 octahedra,  a cornercorner with one Co(2)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-23°. Cr(1) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-5°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(6) atoms to form CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles are 23°. In the second Co site, Co(2) is bonded to one O(2), one O(6), two equivalent O(3), and two equivalent O(5) atoms to form distorted CoO6 octahedra that share  a cornercorner with one Mg(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles are 21°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Cr(1) and two equivalent Co(1) atoms. In the second O site, O(2) is bonded to two equivalent Mg(1), two equivalent Cr(1), and one Co(2) atom to form OMg2Cr2Co square pyramids that share corners with four equivalent O(4)Mg2Cr2Co square pyramids, corners with three equivalent O(6)MgCo3 trigonal pyramids, edges with two equivalent O(2)Mg2Cr2Co square pyramids, and edges with two equivalent O(4)Mg2Cr2Co square pyramids. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Co(1), and two equivalent Co(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Cr(1), and one Co(1) atom to form OMg2Cr2Co square pyramids that share corners with four equivalent O(2)Mg2Cr2Co square pyramids, edges with two equivalent O(2)Mg2Cr2Co square pyramids, edges with two equivalent O(4)Mg2Cr2Co square pyramids, and edges with two equivalent O(6)MgCo3 trigonal pyramids. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Cr(1) and two equivalent Co(2) atoms. In the sixth O site, O(6) is bonded to one Mg(1), one Co(2), and two equivalent Co(1) atoms to form OMgCo3 trigonal pyramids that share corners with three equivalent O(2)Mg2Cr2Co square pyramids, corners with two equivalent O(6)MgCo3 trigonal pyramids, and edges with two equivalent O(4)Mg2Cr2Co square pyramids. is represented by the CIF file [CIF]
data_MgCr(CoO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.643
_cell_length_b   2.894
_cell_length_c   5.886
_cell_angle_alpha   89.998
_cell_angle_beta   101.962
_cell_angle_gamma   77.422
_symmetry_Int_Tables_number   1
_cell_volume   107.915
_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  0.329  0.334  0.831  1.0
  Cr  Cr1  1  0.334  0.331  0.332  1.0
  Co  Co2  1  0.980  0.009  0.027  1.0
  Co  Co3  1  0.698  0.650  0.655  1.0
  O  O4  1  0.023  0.487  0.239  1.0
  O  O5  1  0.345  0.826  0.576  1.0
  O  O6  1  0.660  0.169  0.860  1.0
  O  O7  1  0.326  0.835  0.088  1.0
  O  O8  1  0.652  0.173  0.441  1.0
  O  O9  1  0.993  0.502  0.800  1.0
[/CIF]
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