The structure described by MgCr2O4 crystallizes in the monoclinic P2/m space group. Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share corners with four equivalent Cr(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with four equivalent Cr(1)O6 octahedra, and faces with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with eight equivalent Cr(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with four equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-49°. In the second Cr site, Cr(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CrO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with eight equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-49°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Cr(1), and two equivalent Cr(2) atoms to form a mixture of distorted corner and edge-sharing OMg2Cr3 square pyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Cr(2), and two equivalent Cr(1) atoms. is represented by the CIF card [CIF]
data_MgCr2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.963
_cell_length_b   5.015
_cell_length_c   4.979
_cell_angle_alpha   92.768
_cell_angle_beta   90.000
_cell_angle_gamma   90.001
_symmetry_Int_Tables_number   1
_cell_volume   73.906
_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  0.975  0.500  0.000  1.0
  Cr  Cr1  1  0.476  0.500  0.500  1.0
  Cr  Cr2  1  0.977  0.000  0.000  1.0
  O  O3  1  0.476  0.761  0.155  1.0
  O  O4  1  0.476  0.239  0.845  1.0
  O  O5  1  0.976  0.711  0.682  1.0
  O  O6  1  0.976  0.289  0.318  1.0
[/CIF]
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The structure described by MgCr2O4 crystallizes in the monoclinic P2/m space group. Mg(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form MgO6 octahedra that share corners with four equivalent Cr(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with four equivalent Cr(1)O6 octahedra, and faces with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with eight equivalent Cr(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with four equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-49°. In the second Cr site, Cr(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CrO6 octahedra that share corners with four equivalent Mg(1)O6 octahedra, corners with eight equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and faces with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-49°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Cr(1), and two equivalent Cr(2) atoms to form a mixture of distorted corner and edge-sharing OMg2Cr3 square pyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Cr(2), and two equivalent Cr(1) atoms. is represented by the CIF card [CIF]
data_MgCr2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.963
_cell_length_b   5.015
_cell_length_c   4.979
_cell_angle_alpha   92.768
_cell_angle_beta   90.000
_cell_angle_gamma   90.001
_symmetry_Int_Tables_number   1
_cell_volume   73.906
_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  0.975  0.500  0.000  1.0
  Cr  Cr1  1  0.476  0.500  0.500  1.0
  Cr  Cr2  1  0.977  0.000  0.000  1.0
  O  O3  1  0.476  0.761  0.155  1.0
  O  O4  1  0.476  0.239  0.845  1.0
  O  O5  1  0.976  0.711  0.682  1.0
  O  O6  1  0.976  0.289  0.318  1.0
[/CIF]
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