The material described by CaCu3Cr4O12 crystallizes in the trigonal R-3 space group. Ca(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form CaO12 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 Ca(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 Ca(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 4-coordinate geometry to one Ca(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 Ca(1), two equivalent Cr(1), and one Cu(1) atom. is represented by the CIF card [CIF]
data_CaCr4(CuO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.395
_cell_length_b   6.395
_cell_length_c   6.386
_cell_angle_alpha   70.556
_cell_angle_beta   109.447
_cell_angle_gamma   70.507
_symmetry_Int_Tables_number   1
_cell_volume   201.135
_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
  Ca  Ca0  1  1.000  0.000  0.000  1.0
  Cr  Cr1  1  0.500  0.500  0.500  1.0
  Cr  Cr2  1  0.500  1.000  0.000  1.0
  Cr  Cr3  1  0.000  0.500  1.000  1.0
  Cr  Cr4  1  0.000  0.000  0.500  1.0
  Cu  Cu5  1  0.500  0.000  0.500  1.0
  Cu  Cu6  1  1.000  0.500  0.500  1.0
  Cu  Cu7  1  0.500  0.500  0.000  1.0
  O  O8  1  0.171  0.141  0.690  1.0
  O  O9  1  0.829  0.859  0.310  1.0
  O  O10  1  0.170  0.518  0.311  1.0
  O  O11  1  0.311  0.170  0.141  1.0
  O  O12  1  0.859  0.312  0.169  1.0
  O  O13  1  0.518  0.311  0.830  1.0
  O  O14  1  0.688  0.171  0.519  1.0
  O  O15  1  0.141  0.688  0.831  1.0
  O  O16  1  0.830  0.482  0.689  1.0
  O  O17  1  0.689  0.830  0.859  1.0
  O  O18  1  0.482  0.689  0.170  1.0
  O  O19  1  0.312  0.829  0.481  1.0
[/CIF]
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The material described by CaCu3Cr4O12 crystallizes in the trigonal R-3 space group. Ca(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form CaO12 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 Ca(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 Ca(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 4-coordinate geometry to one Ca(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 Ca(1), two equivalent Cr(1), and one Cu(1) atom. is represented by the CIF card [CIF]
data_CaCr4(CuO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.395
_cell_length_b   6.395
_cell_length_c   6.386
_cell_angle_alpha   70.556
_cell_angle_beta   109.447
_cell_angle_gamma   70.507
_symmetry_Int_Tables_number   1
_cell_volume   201.135
_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
  Ca  Ca0  1  1.000  0.000  0.000  1.0
  Cr  Cr1  1  0.500  0.500  0.500  1.0
  Cr  Cr2  1  0.500  1.000  0.000  1.0
  Cr  Cr3  1  0.000  0.500  1.000  1.0
  Cr  Cr4  1  0.000  0.000  0.500  1.0
  Cu  Cu5  1  0.500  0.000  0.500  1.0
  Cu  Cu6  1  1.000  0.500  0.500  1.0
  Cu  Cu7  1  0.500  0.500  0.000  1.0
  O  O8  1  0.171  0.141  0.690  1.0
  O  O9  1  0.829  0.859  0.310  1.0
  O  O10  1  0.170  0.518  0.311  1.0
  O  O11  1  0.311  0.170  0.141  1.0
  O  O12  1  0.859  0.312  0.169  1.0
  O  O13  1  0.518  0.311  0.830  1.0
  O  O14  1  0.688  0.171  0.519  1.0
  O  O15  1  0.141  0.688  0.831  1.0
  O  O16  1  0.830  0.482  0.689  1.0
  O  O17  1  0.689  0.830  0.859  1.0
  O  O18  1  0.482  0.689  0.170  1.0
  O  O19  1  0.312  0.829  0.481  1.0
[/CIF]
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