The compound described by MgCrO2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO5 trigonal bipyramids that share corners with four equivalent Cr(2)O6 octahedra, edges with two equivalent Mg(1)O5 trigonal bipyramids, and  a faceface with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-52°. In the second Mg site, Mg(2) is bonded in a distorted trigonal non-coplanar geometry to one O(3) and two equivalent O(2) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. In the second Cr site, Cr(2) is bonded to one O(1), two equivalent O(2), and three equivalent O(4) atoms to form CrO6 octahedra that share corners with four equivalent Mg(1)O5 trigonal bipyramids, edges with four equivalent Cr(2)O6 octahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cr(2), and two equivalent Cr(1) atoms to form OMgCr3 tetrahedra that share corners with two equivalent O(1)MgCr3 tetrahedra, corners with four equivalent O(3)Mg3Cr2 trigonal bipyramids, and  an edgeedge with one O(3)Mg3Cr2 trigonal bipyramid. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(2) and two equivalent Cr(2) atoms. In the third O site, O(3) is bonded to one Mg(2), two equivalent Mg(1), and two equivalent Cr(1) atoms to form OMg3Cr2 trigonal bipyramids that share corners with four equivalent O(1)MgCr3 tetrahedra,  an edgeedge with one O(1)MgCr3 tetrahedra, and edges with two equivalent O(3)Mg3Cr2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Mg(1) and three equivalent Cr(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCrO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.114
_cell_length_b   8.114
_cell_length_c   9.625
_cell_angle_alpha   60.586
_cell_angle_beta   60.586
_cell_angle_gamma   20.949
_symmetry_Int_Tables_number   1
_cell_volume   196.276
_cell_formula_units_Z   4
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  0.670  0.670  0.290  1.0
  Mg  Mg1  1  0.330  0.330  0.710  1.0
  Mg  Mg2  1  0.982  0.982  0.363  1.0
  Mg  Mg3  1  0.018  0.018  0.637  1.0
  Cr  Cr4  1  0.360  0.360  0.978  1.0
  Cr  Cr5  1  0.819  0.819  0.345  1.0
  Cr  Cr6  1  0.181  0.181  0.655  1.0
  Cr  Cr7  1  0.640  0.640  0.022  1.0
  O  O8  1  0.177  0.177  0.861  1.0
  O  O9  1  0.580  0.580  0.700  1.0
  O  O10  1  0.420  0.420  0.300  1.0
  O  O11  1  0.823  0.823  0.139  1.0
  O  O12  1  0.873  0.873  0.810  1.0
  O  O13  1  0.213  0.213  0.414  1.0
  O  O14  1  0.127  0.127  0.190  1.0
  O  O15  1  0.787  0.787  0.586  1.0
[/CIF]
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The compound described by MgCrO2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO5 trigonal bipyramids that share corners with four equivalent Cr(2)O6 octahedra, edges with two equivalent Mg(1)O5 trigonal bipyramids, and  a faceface with one Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-52°. In the second Mg site, Mg(2) is bonded in a distorted trigonal non-coplanar geometry to one O(3) and two equivalent O(2) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. In the second Cr site, Cr(2) is bonded to one O(1), two equivalent O(2), and three equivalent O(4) atoms to form CrO6 octahedra that share corners with four equivalent Mg(1)O5 trigonal bipyramids, edges with four equivalent Cr(2)O6 octahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cr(2), and two equivalent Cr(1) atoms to form OMgCr3 tetrahedra that share corners with two equivalent O(1)MgCr3 tetrahedra, corners with four equivalent O(3)Mg3Cr2 trigonal bipyramids, and  an edgeedge with one O(3)Mg3Cr2 trigonal bipyramid. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(2) and two equivalent Cr(2) atoms. In the third O site, O(3) is bonded to one Mg(2), two equivalent Mg(1), and two equivalent Cr(1) atoms to form OMg3Cr2 trigonal bipyramids that share corners with four equivalent O(1)MgCr3 tetrahedra,  an edgeedge with one O(1)MgCr3 tetrahedra, and edges with two equivalent O(3)Mg3Cr2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Mg(1) and three equivalent Cr(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCrO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.114
_cell_length_b   8.114
_cell_length_c   9.625
_cell_angle_alpha   60.586
_cell_angle_beta   60.586
_cell_angle_gamma   20.949
_symmetry_Int_Tables_number   1
_cell_volume   196.276
_cell_formula_units_Z   4
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  0.670  0.670  0.290  1.0
  Mg  Mg1  1  0.330  0.330  0.710  1.0
  Mg  Mg2  1  0.982  0.982  0.363  1.0
  Mg  Mg3  1  0.018  0.018  0.637  1.0
  Cr  Cr4  1  0.360  0.360  0.978  1.0
  Cr  Cr5  1  0.819  0.819  0.345  1.0
  Cr  Cr6  1  0.181  0.181  0.655  1.0
  Cr  Cr7  1  0.640  0.640  0.022  1.0
  O  O8  1  0.177  0.177  0.861  1.0
  O  O9  1  0.580  0.580  0.700  1.0
  O  O10  1  0.420  0.420  0.300  1.0
  O  O11  1  0.823  0.823  0.139  1.0
  O  O12  1  0.873  0.873  0.810  1.0
  O  O13  1  0.213  0.213  0.414  1.0
  O  O14  1  0.127  0.127  0.190  1.0
  O  O15  1  0.787  0.787  0.586  1.0
[/CIF]
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