The structure described by CaCr2O4 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(3), two equivalent O(1), and three equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 49-59°. In the second Cr site, Cr(2) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 49-59°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Ca(1), one Cr(2), and two equivalent Cr(1) atoms. In the second O site, O(2) is bonded to two equivalent Ca(1) and three equivalent Cr(2) atoms to form a mixture of corner and edge-sharing OCa2Cr3 square pyramids. In the third O site, O(3) is bonded to two equivalent Ca(1), one Cr(1), and two equivalent Cr(2) atoms to form a mixture of distorted corner and edge-sharing OCa2Cr3 trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and three equivalent Cr(1) atoms to form a mixture of distorted corner and edge-sharing OCa2Cr3 trigonal bipyramids. is represented by the CIF card [CIF]
data_CaCr2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.990
_cell_length_b   9.064
_cell_length_c   10.630
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   288.128
_cell_formula_units_Z   4
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  0.750  0.240  0.341  1.0
  Ca  Ca1  1  0.250  0.760  0.659  1.0
  Ca  Ca2  1  0.750  0.740  0.159  1.0
  Ca  Ca3  1  0.250  0.260  0.841  1.0
  Cr  Cr4  1  0.750  0.060  0.113  1.0
  Cr  Cr5  1  0.250  0.940  0.887  1.0
  Cr  Cr6  1  0.750  0.584  0.899  1.0
  Cr  Cr7  1  0.250  0.416  0.101  1.0
  Cr  Cr8  1  0.750  0.560  0.387  1.0
  Cr  Cr9  1  0.250  0.440  0.613  1.0
  Cr  Cr10  1  0.750  0.084  0.601  1.0
  Cr  Cr11  1  0.250  0.916  0.399  1.0
  O  O12  1  0.750  0.798  0.839  1.0
  O  O13  1  0.250  0.202  0.161  1.0
  O  O14  1  0.750  0.298  0.661  1.0
  O  O15  1  0.250  0.702  0.339  1.0
  O  O16  1  0.750  0.883  0.524  1.0
  O  O17  1  0.250  0.117  0.476  1.0
  O  O18  1  0.750  0.383  0.976  1.0
  O  O19  1  0.250  0.617  0.024  1.0
  O  O20  1  0.750  0.472  0.214  1.0
  O  O21  1  0.250  0.528  0.786  1.0
  O  O22  1  0.750  0.972  0.286  1.0
  O  O23  1  0.250  0.028  0.714  1.0
  O  O24  1  0.750  0.581  0.573  1.0
  O  O25  1  0.250  0.419  0.427  1.0
  O  O26  1  0.750  0.081  0.927  1.0
  O  O27  1  0.250  0.919  0.073  1.0
[/CIF]
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The structure described by CaCr2O4 crystallizes in the orthorhombic Pnma space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(3), two equivalent O(1), and three equivalent O(4) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 49-59°. In the second Cr site, Cr(2) is bonded to one O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of corner and edge-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 49-59°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Ca(1), one Cr(2), and two equivalent Cr(1) atoms. In the second O site, O(2) is bonded to two equivalent Ca(1) and three equivalent Cr(2) atoms to form a mixture of corner and edge-sharing OCa2Cr3 square pyramids. In the third O site, O(3) is bonded to two equivalent Ca(1), one Cr(1), and two equivalent Cr(2) atoms to form a mixture of distorted corner and edge-sharing OCa2Cr3 trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and three equivalent Cr(1) atoms to form a mixture of distorted corner and edge-sharing OCa2Cr3 trigonal bipyramids. is represented by the CIF card [CIF]
data_CaCr2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.990
_cell_length_b   9.064
_cell_length_c   10.630
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   288.128
_cell_formula_units_Z   4
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  0.750  0.240  0.341  1.0
  Ca  Ca1  1  0.250  0.760  0.659  1.0
  Ca  Ca2  1  0.750  0.740  0.159  1.0
  Ca  Ca3  1  0.250  0.260  0.841  1.0
  Cr  Cr4  1  0.750  0.060  0.113  1.0
  Cr  Cr5  1  0.250  0.940  0.887  1.0
  Cr  Cr6  1  0.750  0.584  0.899  1.0
  Cr  Cr7  1  0.250  0.416  0.101  1.0
  Cr  Cr8  1  0.750  0.560  0.387  1.0
  Cr  Cr9  1  0.250  0.440  0.613  1.0
  Cr  Cr10  1  0.750  0.084  0.601  1.0
  Cr  Cr11  1  0.250  0.916  0.399  1.0
  O  O12  1  0.750  0.798  0.839  1.0
  O  O13  1  0.250  0.202  0.161  1.0
  O  O14  1  0.750  0.298  0.661  1.0
  O  O15  1  0.250  0.702  0.339  1.0
  O  O16  1  0.750  0.883  0.524  1.0
  O  O17  1  0.250  0.117  0.476  1.0
  O  O18  1  0.750  0.383  0.976  1.0
  O  O19  1  0.250  0.617  0.024  1.0
  O  O20  1  0.750  0.472  0.214  1.0
  O  O21  1  0.250  0.528  0.786  1.0
  O  O22  1  0.750  0.972  0.286  1.0
  O  O23  1  0.250  0.028  0.714  1.0
  O  O24  1  0.750  0.581  0.573  1.0
  O  O25  1  0.250  0.419  0.427  1.0
  O  O26  1  0.750  0.081  0.927  1.0
  O  O27  1  0.250  0.919  0.073  1.0
[/CIF]
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