The compound described by MgCr4O12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(10), one O(11), and one O(8) atom to form MgO4 tetrahedra that share  a cornercorner with one Cr(1)O4 tetrahedra,  a cornercorner with one Cr(2)O4 tetrahedra,  a cornercorner with one Cr(3)O4 tetrahedra, and  a cornercorner with one Cr(4)O4 tetrahedra. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form CrO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra and corners with two equivalent Cr(2)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(3), one O(4), one O(6), and one O(8) atom to form CrO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra and corners with two equivalent Cr(1)O4 tetrahedra. In the third Cr site, Cr(3) is bonded to one O(10), one O(5), one O(7), and one O(9) atom to form CrO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra and corners with two equivalent Cr(4)O4 tetrahedra. In the fourth Cr site, Cr(4) is bonded to one O(11), one O(12), one O(7), and one O(9) atom to form CrO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra and corners with two equivalent Cr(3)O4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one Cr(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Cr(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one Cr(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cr(2) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Cr(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cr(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Cr(3) and one Cr(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Mg(1) and one Cr(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Cr(3) and one Cr(4) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Mg(1) and one Cr(3) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Mg(1) and one Cr(4) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Cr(4) atom. is represented by the CIF file [CIF]
data_MgCr4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.028
_cell_length_b   8.046
_cell_length_c   5.545
_cell_angle_alpha   70.762
_cell_angle_beta   109.213
_cell_angle_gamma   93.453
_symmetry_Int_Tables_number   1
_cell_volume   318.892
_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  0.801  0.802  0.748  1.0
  Cr  Cr1  1  0.190  0.609  0.802  1.0
  Cr  Cr2  1  0.385  0.771  0.304  1.0
  Cr  Cr3  1  0.610  0.189  0.701  1.0
  Cr  Cr4  1  0.769  0.387  0.195  1.0
  O  O5  1  0.020  0.754  0.691  1.0
  O  O6  1  0.152  0.405  0.900  1.0
  O  O7  1  0.266  0.949  0.151  1.0
  O  O8  1  0.320  0.646  0.569  1.0
  O  O9  1  0.407  0.149  0.600  1.0
  O  O10  1  0.363  0.657  0.083  1.0
  O  O11  1  0.644  0.315  0.937  1.0
  O  O12  1  0.596  0.816  0.420  1.0
  O  O13  1  0.657  0.364  0.422  1.0
  O  O14  1  0.757  0.020  0.810  1.0
  O  O15  1  0.807  0.598  0.072  1.0
  O  O16  1  0.950  0.272  0.346  1.0
[/CIF]
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The compound described by MgCr4O12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(10), one O(11), and one O(8) atom to form MgO4 tetrahedra that share  a cornercorner with one Cr(1)O4 tetrahedra,  a cornercorner with one Cr(2)O4 tetrahedra,  a cornercorner with one Cr(3)O4 tetrahedra, and  a cornercorner with one Cr(4)O4 tetrahedra. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form CrO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra and corners with two equivalent Cr(2)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(3), one O(4), one O(6), and one O(8) atom to form CrO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra and corners with two equivalent Cr(1)O4 tetrahedra. In the third Cr site, Cr(3) is bonded to one O(10), one O(5), one O(7), and one O(9) atom to form CrO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra and corners with two equivalent Cr(4)O4 tetrahedra. In the fourth Cr site, Cr(4) is bonded to one O(11), one O(12), one O(7), and one O(9) atom to form CrO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra and corners with two equivalent Cr(3)O4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one Cr(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Cr(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one Cr(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cr(2) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one Cr(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Cr(1) and one Cr(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Cr(3) and one Cr(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Mg(1) and one Cr(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Cr(3) and one Cr(4) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Mg(1) and one Cr(3) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Mg(1) and one Cr(4) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Cr(4) atom. is represented by the CIF file [CIF]
data_MgCr4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.028
_cell_length_b   8.046
_cell_length_c   5.545
_cell_angle_alpha   70.762
_cell_angle_beta   109.213
_cell_angle_gamma   93.453
_symmetry_Int_Tables_number   1
_cell_volume   318.892
_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  0.801  0.802  0.748  1.0
  Cr  Cr1  1  0.190  0.609  0.802  1.0
  Cr  Cr2  1  0.385  0.771  0.304  1.0
  Cr  Cr3  1  0.610  0.189  0.701  1.0
  Cr  Cr4  1  0.769  0.387  0.195  1.0
  O  O5  1  0.020  0.754  0.691  1.0
  O  O6  1  0.152  0.405  0.900  1.0
  O  O7  1  0.266  0.949  0.151  1.0
  O  O8  1  0.320  0.646  0.569  1.0
  O  O9  1  0.407  0.149  0.600  1.0
  O  O10  1  0.363  0.657  0.083  1.0
  O  O11  1  0.644  0.315  0.937  1.0
  O  O12  1  0.596  0.816  0.420  1.0
  O  O13  1  0.657  0.364  0.422  1.0
  O  O14  1  0.757  0.020  0.810  1.0
  O  O15  1  0.807  0.598  0.072  1.0
  O  O16  1  0.950  0.272  0.346  1.0
[/CIF]
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