The compound described by MgCr4O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a see-saw-like geometry to one O(1), one O(4), and two equivalent O(5) atoms. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(3), one O(5), two equivalent O(4), and two equivalent O(7) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 6-10°. In the second Cr site, Cr(2) is bonded to one O(4), one O(6), two equivalent O(3), and two equivalent O(7) atoms to form a mixture of distorted corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 6-39°. In the third Cr site, Cr(3) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 6-10°. In the fourth Cr site, Cr(4) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 6-39°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cr(4), and two equivalent Cr(3) atoms to form corner-sharing OMgCr3 trigonal pyramids. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Cr(3) and two equivalent Cr(4) atoms. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Cr(1) and two equivalent Cr(2) atoms. In the fourth O site, O(4) is bonded to one Mg(1), one Cr(2), and two equivalent Cr(1) atoms to form corner-sharing OMgCr3 trigonal pyramids. In the fifth O site, O(5) is bonded in a see-saw-like geometry to two equivalent Mg(1), one Cr(1), and one Cr(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Cr(2) and one Cr(4) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to two equivalent Cr(1) and two equivalent Cr(2) atoms. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to two equivalent Cr(3) and two equivalent Cr(4) atoms. is represented by the CIF file [CIF]
data_MgCr4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.995
_cell_length_b   4.936
_cell_length_c   10.681
_cell_angle_alpha   89.926
_cell_angle_beta   89.816
_cell_angle_gamma   107.519
_symmetry_Int_Tables_number   1
_cell_volume   150.600
_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  0.267  0.533  0.250  1.0
  Cr  Cr1  1  0.881  0.758  0.039  1.0
  Cr  Cr2  1  0.129  0.286  0.908  1.0
  Cr  Cr3  1  0.872  0.750  0.460  1.0
  Cr  Cr4  1  0.157  0.277  0.592  1.0
  O  O5  1  0.239  0.480  0.428  1.0
  O  O6  1  0.782  0.530  0.618  1.0
  O  O7  1  0.755  0.539  0.882  1.0
  O  O8  1  0.247  0.488  0.072  1.0
  O  O9  1  0.897  0.794  0.252  1.0
  O  O10  1  0.081  0.155  0.751  1.0
  O  O11  1  0.535  0.034  0.982  1.0
  O  O12  1  0.493  0.025  0.519  1.0
[/CIF]
.
The compound described by MgCr4O8 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a see-saw-like geometry to one O(1), one O(4), and two equivalent O(5) atoms. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(3), one O(5), two equivalent O(4), and two equivalent O(7) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 6-10°. In the second Cr site, Cr(2) is bonded to one O(4), one O(6), two equivalent O(3), and two equivalent O(7) atoms to form a mixture of distorted corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 6-39°. In the third Cr site, Cr(3) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(8) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 6-10°. In the fourth Cr site, Cr(4) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form a mixture of distorted corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 6-39°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cr(4), and two equivalent Cr(3) atoms to form corner-sharing OMgCr3 trigonal pyramids. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to one Cr(3) and two equivalent Cr(4) atoms. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to one Cr(1) and two equivalent Cr(2) atoms. In the fourth O site, O(4) is bonded to one Mg(1), one Cr(2), and two equivalent Cr(1) atoms to form corner-sharing OMgCr3 trigonal pyramids. In the fifth O site, O(5) is bonded in a see-saw-like geometry to two equivalent Mg(1), one Cr(1), and one Cr(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Cr(2) and one Cr(4) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to two equivalent Cr(1) and two equivalent Cr(2) atoms. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to two equivalent Cr(3) and two equivalent Cr(4) atoms. is represented by the CIF file [CIF]
data_MgCr4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.995
_cell_length_b   4.936
_cell_length_c   10.681
_cell_angle_alpha   89.926
_cell_angle_beta   89.816
_cell_angle_gamma   107.519
_symmetry_Int_Tables_number   1
_cell_volume   150.600
_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  0.267  0.533  0.250  1.0
  Cr  Cr1  1  0.881  0.758  0.039  1.0
  Cr  Cr2  1  0.129  0.286  0.908  1.0
  Cr  Cr3  1  0.872  0.750  0.460  1.0
  Cr  Cr4  1  0.157  0.277  0.592  1.0
  O  O5  1  0.239  0.480  0.428  1.0
  O  O6  1  0.782  0.530  0.618  1.0
  O  O7  1  0.755  0.539  0.882  1.0
  O  O8  1  0.247  0.488  0.072  1.0
  O  O9  1  0.897  0.794  0.252  1.0
  O  O10  1  0.081  0.155  0.751  1.0
  O  O11  1  0.535  0.034  0.982  1.0
  O  O12  1  0.493  0.025  0.519  1.0
[/CIF]
.