The compound described by Ca3Cr2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(4), two equivalent O(3), and three equivalent O(2) atoms. Cr(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 21-25°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1) and two equivalent Cr(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one Cr(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Cr(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Cr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.403
_cell_length_b   10.023
_cell_length_c   5.419
_cell_angle_alpha   90.000
_cell_angle_beta   90.001
_cell_angle_gamma   105.637
_symmetry_Int_Tables_number   1
_cell_volume   282.643
_cell_formula_units_Z   2
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  0.756  1.000  0.710  1.0
  Ca  Ca1  1  0.244  1.000  0.210  1.0
  Ca  Ca2  1  0.573  0.628  0.786  1.0
  Ca  Ca3  1  0.427  0.372  0.286  1.0
  Ca  Ca4  1  0.944  0.372  0.786  1.0
  Ca  Ca5  1  0.056  0.628  0.286  1.0
  Cr  Cr6  1  0.847  0.197  0.251  1.0
  Cr  Cr7  1  0.153  0.803  0.751  1.0
  Cr  Cr8  1  0.350  0.197  0.751  1.0
  Cr  Cr9  1  0.650  0.803  0.251  1.0
  O  O10  1  0.317  1.000  0.765  1.0
  O  O11  1  0.683  0.000  0.265  1.0
  O  O12  1  0.998  0.607  0.734  1.0
  O  O13  1  0.002  0.393  0.234  1.0
  O  O14  1  0.609  0.607  0.234  1.0
  O  O15  1  0.391  0.393  0.734  1.0
  O  O16  1  0.344  0.779  0.035  1.0
  O  O17  1  0.656  0.221  0.535  1.0
  O  O18  1  0.435  0.779  0.535  1.0
  O  O19  1  0.565  0.221  0.035  1.0
  O  O20  1  0.870  0.832  0.966  1.0
  O  O21  1  0.130  0.168  0.466  1.0
  O  O22  1  0.038  0.168  0.966  1.0
  O  O23  1  0.962  0.832  0.466  1.0
[/CIF]
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The compound described by Ca3Cr2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(4), two equivalent O(3), and three equivalent O(2) atoms. Cr(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form corner-sharing CrO6 octahedra. The corner-sharing octahedral tilt angles range from 21-25°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1) and two equivalent Cr(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one Cr(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Cr(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Cr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.403
_cell_length_b   10.023
_cell_length_c   5.419
_cell_angle_alpha   90.000
_cell_angle_beta   90.001
_cell_angle_gamma   105.637
_symmetry_Int_Tables_number   1
_cell_volume   282.643
_cell_formula_units_Z   2
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  0.756  1.000  0.710  1.0
  Ca  Ca1  1  0.244  1.000  0.210  1.0
  Ca  Ca2  1  0.573  0.628  0.786  1.0
  Ca  Ca3  1  0.427  0.372  0.286  1.0
  Ca  Ca4  1  0.944  0.372  0.786  1.0
  Ca  Ca5  1  0.056  0.628  0.286  1.0
  Cr  Cr6  1  0.847  0.197  0.251  1.0
  Cr  Cr7  1  0.153  0.803  0.751  1.0
  Cr  Cr8  1  0.350  0.197  0.751  1.0
  Cr  Cr9  1  0.650  0.803  0.251  1.0
  O  O10  1  0.317  1.000  0.765  1.0
  O  O11  1  0.683  0.000  0.265  1.0
  O  O12  1  0.998  0.607  0.734  1.0
  O  O13  1  0.002  0.393  0.234  1.0
  O  O14  1  0.609  0.607  0.234  1.0
  O  O15  1  0.391  0.393  0.734  1.0
  O  O16  1  0.344  0.779  0.035  1.0
  O  O17  1  0.656  0.221  0.535  1.0
  O  O18  1  0.435  0.779  0.535  1.0
  O  O19  1  0.565  0.221  0.035  1.0
  O  O20  1  0.870  0.832  0.966  1.0
  O  O21  1  0.130  0.168  0.466  1.0
  O  O22  1  0.038  0.168  0.966  1.0
  O  O23  1  0.962  0.832  0.466  1.0
[/CIF]
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