The material structure described by K2Cr2O7 crystallizes in the monoclinic C2/c space group. K(1) is bonded in a 8-coordinate geometry to two equivalent O(4), three equivalent O(1), and three equivalent O(2) atoms. Cr(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing CrO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent K(1) and one Cr(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent K(1) and one Cr(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Cr(1) atom. is represented by the CIF card [CIF]
data_K2Cr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.446
_cell_length_b   7.446
_cell_length_c   7.413
_cell_angle_alpha   88.468
_cell_angle_beta   88.468
_cell_angle_gamma   59.283
_symmetry_Int_Tables_number   1
_cell_volume   353.141
_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
  K  K0  1  0.998  0.709  0.860  1.0
  K  K1  1  0.291  0.002  0.640  1.0
  K  K2  1  0.002  0.291  0.140  1.0
  K  K3  1  0.709  0.998  0.360  1.0
  Cr  Cr4  1  0.776  0.430  0.632  1.0
  Cr  Cr5  1  0.570  0.224  0.868  1.0
  Cr  Cr6  1  0.224  0.570  0.368  1.0
  Cr  Cr7  1  0.430  0.776  0.132  1.0
  O  O8  1  0.864  0.252  0.479  1.0
  O  O9  1  0.748  0.136  0.021  1.0
  O  O10  1  0.136  0.748  0.521  1.0
  O  O11  1  0.252  0.864  0.979  1.0
  O  O12  1  0.962  0.367  0.775  1.0
  O  O13  1  0.633  0.038  0.725  1.0
  O  O14  1  0.038  0.633  0.225  1.0
  O  O15  1  0.367  0.962  0.275  1.0
  O  O16  1  0.563  0.437  0.750  1.0
  O  O17  1  0.437  0.563  0.250  1.0
  O  O18  1  0.701  0.658  0.545  1.0
  O  O19  1  0.342  0.299  0.955  1.0
  O  O20  1  0.299  0.342  0.455  1.0
  O  O21  1  0.658  0.701  0.045  1.0
[/CIF]
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The material structure described by K2Cr2O7 crystallizes in the monoclinic C2/c space group. K(1) is bonded in a 8-coordinate geometry to two equivalent O(4), three equivalent O(1), and three equivalent O(2) atoms. Cr(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing CrO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent K(1) and one Cr(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent K(1) and one Cr(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Cr(1) atom. is represented by the CIF card [CIF]
data_K2Cr2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.446
_cell_length_b   7.446
_cell_length_c   7.413
_cell_angle_alpha   88.468
_cell_angle_beta   88.468
_cell_angle_gamma   59.283
_symmetry_Int_Tables_number   1
_cell_volume   353.141
_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
  K  K0  1  0.998  0.709  0.860  1.0
  K  K1  1  0.291  0.002  0.640  1.0
  K  K2  1  0.002  0.291  0.140  1.0
  K  K3  1  0.709  0.998  0.360  1.0
  Cr  Cr4  1  0.776  0.430  0.632  1.0
  Cr  Cr5  1  0.570  0.224  0.868  1.0
  Cr  Cr6  1  0.224  0.570  0.368  1.0
  Cr  Cr7  1  0.430  0.776  0.132  1.0
  O  O8  1  0.864  0.252  0.479  1.0
  O  O9  1  0.748  0.136  0.021  1.0
  O  O10  1  0.136  0.748  0.521  1.0
  O  O11  1  0.252  0.864  0.979  1.0
  O  O12  1  0.962  0.367  0.775  1.0
  O  O13  1  0.633  0.038  0.725  1.0
  O  O14  1  0.038  0.633  0.225  1.0
  O  O15  1  0.367  0.962  0.275  1.0
  O  O16  1  0.563  0.437  0.750  1.0
  O  O17  1  0.437  0.563  0.250  1.0
  O  O18  1  0.701  0.658  0.545  1.0
  O  O19  1  0.342  0.299  0.955  1.0
  O  O20  1  0.299  0.342  0.455  1.0
  O  O21  1  0.658  0.701  0.045  1.0
[/CIF]
.