The compound described by MgCr2(CoO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form distorted MgO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Co(2)O6 octahedra, corners with two equivalent Cr(2)O4 tetrahedra, and  an edgeedge with one Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 66-68°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form CrO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Co(2)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-58°. In the second Cr site, Cr(2) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form CrO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Co(2)O6 octahedra, and corners with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-51°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form CoO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra, and edges with two equivalent Co(2)O6 octahedra. In the second Co site, Co(2) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form CoO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra, and edges with two equivalent Co(1)O6 octahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cr(1) and one Co(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mg(1), one Cr(2), and one Co(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Cr(2), one Co(1), and one Co(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cr(2), one Co(1), and one Co(2) atom. In the fifth O site, O(5) is bonded to one Mg(1), one Cr(1), one Co(1), and one Co(2) atom to form distorted edge-sharing OMgCrCo2 tetrahedra. In the sixth O site, O(6) is bonded to one Mg(1), one Cr(1), one Co(1), and one Co(2) atom to form distorted edge-sharing OMgCrCo2 tetrahedra. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cr(1) and one Co(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Mg(1), one Cr(2), and one Co(2) atom. is represented by the CIF card [CIF]
data_MgCr2(CoO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.154
_cell_length_b   5.158
_cell_length_c   6.357
_cell_angle_alpha   89.991
_cell_angle_beta   89.999
_cell_angle_gamma   112.912
_symmetry_Int_Tables_number   1
_cell_volume   155.666
_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  0.663  0.337  0.750  1.0
  Cr  Cr1  1  0.341  0.658  0.750  1.0
  Cr  Cr2  1  0.639  0.362  0.250  1.0
  Co  Co3  1  0.999  0.000  0.005  1.0
  Co  Co4  1  0.999  1.000  0.495  1.0
  O  O5  1  0.237  0.762  0.530  1.0
  O  O6  1  0.763  0.238  0.029  1.0
  O  O7  1  0.789  0.725  0.250  1.0
  O  O8  1  0.278  0.214  0.250  1.0
  O  O9  1  0.245  0.275  0.750  1.0
  O  O10  1  0.724  0.754  0.750  1.0
  O  O11  1  0.236  0.763  0.968  1.0
  O  O12  1  0.763  0.238  0.472  1.0
[/CIF]
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The compound described by MgCr2(CoO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(5), one O(6), and one O(8) atom to form distorted MgO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Co(2)O6 octahedra, corners with two equivalent Cr(2)O4 tetrahedra, and  an edgeedge with one Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 66-68°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form CrO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Co(2)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-58°. In the second Cr site, Cr(2) is bonded to one O(2), one O(3), one O(4), and one O(8) atom to form CrO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Co(2)O6 octahedra, and corners with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-51°. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form CoO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra, and edges with two equivalent Co(2)O6 octahedra. In the second Co site, Co(2) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form CoO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra, and edges with two equivalent Co(1)O6 octahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cr(1) and one Co(2) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mg(1), one Cr(2), and one Co(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Cr(2), one Co(1), and one Co(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Cr(2), one Co(1), and one Co(2) atom. In the fifth O site, O(5) is bonded to one Mg(1), one Cr(1), one Co(1), and one Co(2) atom to form distorted edge-sharing OMgCrCo2 tetrahedra. In the sixth O site, O(6) is bonded to one Mg(1), one Cr(1), one Co(1), and one Co(2) atom to form distorted edge-sharing OMgCrCo2 tetrahedra. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Cr(1) and one Co(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Mg(1), one Cr(2), and one Co(2) atom. is represented by the CIF card [CIF]
data_MgCr2(CoO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.154
_cell_length_b   5.158
_cell_length_c   6.357
_cell_angle_alpha   89.991
_cell_angle_beta   89.999
_cell_angle_gamma   112.912
_symmetry_Int_Tables_number   1
_cell_volume   155.666
_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  0.663  0.337  0.750  1.0
  Cr  Cr1  1  0.341  0.658  0.750  1.0
  Cr  Cr2  1  0.639  0.362  0.250  1.0
  Co  Co3  1  0.999  0.000  0.005  1.0
  Co  Co4  1  0.999  1.000  0.495  1.0
  O  O5  1  0.237  0.762  0.530  1.0
  O  O6  1  0.763  0.238  0.029  1.0
  O  O7  1  0.789  0.725  0.250  1.0
  O  O8  1  0.278  0.214  0.250  1.0
  O  O9  1  0.245  0.275  0.750  1.0
  O  O10  1  0.724  0.754  0.750  1.0
  O  O11  1  0.236  0.763  0.968  1.0
  O  O12  1  0.763  0.238  0.472  1.0
[/CIF]
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