The material described by MgCr4(CuO4)3 crystallizes in the trigonal R-3 space group. Mg(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form MgO12 cuboctahedra that share faces with two equivalent Cr(2)O6 octahedra and faces with six equivalent Cr(1)O6 octahedra. 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 two equivalent Cr(2)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, and faces with two equivalent Mg(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. In the second Cr site, Cr(2) is bonded to six equivalent O(1) atoms to form CrO6 octahedra that share corners with six equivalent Cr(1)O6 octahedra and faces with two equivalent Mg(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. Cu(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Cr(1), one Cr(2), and one Cu(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), two equivalent Cr(1), and one Cu(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCr4(CuO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.344
_cell_length_b   6.355
_cell_length_c   6.355
_cell_angle_alpha   109.504
_cell_angle_beta   109.433
_cell_angle_gamma   109.435
_symmetry_Int_Tables_number   1
_cell_volume   197.310
_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  0.000  0.000  0.000  1.0
  Cr  Cr1  1  1.000  0.000  0.500  1.0
  Cr  Cr2  1  1.000  0.500  1.000  1.0
  Cr  Cr3  1  0.500  0.500  0.500  1.0
  Cr  Cr4  1  0.500  1.000  1.000  1.0
  Cu  Cu5  1  0.500  0.500  0.000  1.0
  Cu  Cu6  1  0.000  0.500  0.500  1.0
  Cu  Cu7  1  0.500  1.000  0.500  1.0
  O  O8  1  0.832  0.309  0.140  1.0
  O  O9  1  0.168  0.691  0.860  1.0
  O  O10  1  0.831  0.691  0.522  1.0
  O  O11  1  0.309  0.478  0.169  1.0
  O  O12  1  0.477  0.169  0.309  1.0
  O  O13  1  0.140  0.831  0.309  1.0
  O  O14  1  0.692  0.860  0.169  1.0
  O  O15  1  0.523  0.831  0.691  1.0
  O  O16  1  0.169  0.309  0.478  1.0
  O  O17  1  0.691  0.522  0.831  1.0
  O  O18  1  0.860  0.169  0.691  1.0
  O  O19  1  0.308  0.140  0.831  1.0
[/CIF]
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The material described by MgCr4(CuO4)3 crystallizes in the trigonal R-3 space group. Mg(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form MgO12 cuboctahedra that share faces with two equivalent Cr(2)O6 octahedra and faces with six equivalent Cr(1)O6 octahedra. 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 two equivalent Cr(2)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, and faces with two equivalent Mg(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. In the second Cr site, Cr(2) is bonded to six equivalent O(1) atoms to form CrO6 octahedra that share corners with six equivalent Cr(1)O6 octahedra and faces with two equivalent Mg(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 44°. Cu(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Cr(1), one Cr(2), and one Cu(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), two equivalent Cr(1), and one Cu(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCr4(CuO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.344
_cell_length_b   6.355
_cell_length_c   6.355
_cell_angle_alpha   109.504
_cell_angle_beta   109.433
_cell_angle_gamma   109.435
_symmetry_Int_Tables_number   1
_cell_volume   197.310
_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  0.000  0.000  0.000  1.0
  Cr  Cr1  1  1.000  0.000  0.500  1.0
  Cr  Cr2  1  1.000  0.500  1.000  1.0
  Cr  Cr3  1  0.500  0.500  0.500  1.0
  Cr  Cr4  1  0.500  1.000  1.000  1.0
  Cu  Cu5  1  0.500  0.500  0.000  1.0
  Cu  Cu6  1  0.000  0.500  0.500  1.0
  Cu  Cu7  1  0.500  1.000  0.500  1.0
  O  O8  1  0.832  0.309  0.140  1.0
  O  O9  1  0.168  0.691  0.860  1.0
  O  O10  1  0.831  0.691  0.522  1.0
  O  O11  1  0.309  0.478  0.169  1.0
  O  O12  1  0.477  0.169  0.309  1.0
  O  O13  1  0.140  0.831  0.309  1.0
  O  O14  1  0.692  0.860  0.169  1.0
  O  O15  1  0.523  0.831  0.691  1.0
  O  O16  1  0.169  0.309  0.478  1.0
  O  O17  1  0.691  0.522  0.831  1.0
  O  O18  1  0.860  0.169  0.691  1.0
  O  O19  1  0.308  0.140  0.831  1.0
[/CIF]
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