The compound described by Na2Cr7O14 crystallizes in the trigonal R-3m space group. Na(1) is bonded in a 9-coordinate geometry to nine equivalent O(3) atoms. There are three 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 four equivalent Cr(3)O6 octahedra, corners with two equivalent Cr(2)O4 tetrahedra, and edges with four equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the second Cr site, Cr(2) is bonded to one O(1) and three equivalent O(3) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-57°. In the third Cr site, Cr(3) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form CrO6 octahedra that share corners with six equivalent Cr(1)O6 octahedra and corners with three equivalent Cr(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2) and three equivalent Cr(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Cr(3) and two equivalent Cr(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to three equivalent Na(1), one Cr(2), and one Cr(3) atom. is represented by the CIF card [CIF]
data_Na2Cr7O14
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.948
_cell_length_b   9.948
_cell_length_c   9.948
_cell_angle_alpha   33.627
_cell_angle_beta   33.627
_cell_angle_gamma   33.627
_symmetry_Int_Tables_number   1
_cell_volume   268.980
_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
  Na  Na0  1  0.302  0.302  0.302  1.0
  Na  Na1  1  0.698  0.698  0.698  1.0
  Cr  Cr2  1  0.500  0.000  0.000  1.0
  Cr  Cr3  1  0.060  0.060  0.060  1.0
  Cr  Cr4  1  0.000  0.000  0.500  1.0
  Cr  Cr5  1  0.000  0.500  0.000  1.0
  Cr  Cr6  1  0.576  0.576  0.576  1.0
  Cr  Cr7  1  0.424  0.424  0.424  1.0
  Cr  Cr8  1  0.940  0.940  0.940  1.0
  O  O9  1  0.129  0.129  0.129  1.0
  O  O10  1  0.637  0.116  0.637  1.0
  O  O11  1  0.884  0.363  0.363  1.0
  O  O12  1  0.778  0.299  0.778  1.0
  O  O13  1  0.701  0.222  0.222  1.0
  O  O14  1  0.222  0.222  0.701  1.0
  O  O15  1  0.363  0.363  0.884  1.0
  O  O16  1  0.637  0.637  0.116  1.0
  O  O17  1  0.778  0.778  0.299  1.0
  O  O18  1  0.299  0.778  0.778  1.0
  O  O19  1  0.222  0.701  0.222  1.0
  O  O20  1  0.116  0.637  0.637  1.0
  O  O21  1  0.363  0.884  0.363  1.0
  O  O22  1  0.871  0.871  0.871  1.0
[/CIF]
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The compound described by Na2Cr7O14 crystallizes in the trigonal R-3m space group. Na(1) is bonded in a 9-coordinate geometry to nine equivalent O(3) atoms. There are three 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 four equivalent Cr(3)O6 octahedra, corners with two equivalent Cr(2)O4 tetrahedra, and edges with four equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the second Cr site, Cr(2) is bonded to one O(1) and three equivalent O(3) atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-57°. In the third Cr site, Cr(3) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form CrO6 octahedra that share corners with six equivalent Cr(1)O6 octahedra and corners with three equivalent Cr(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Cr(2) and three equivalent Cr(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Cr(3) and two equivalent Cr(1) atoms. In the third O site, O(3) is bonded in a 2-coordinate geometry to three equivalent Na(1), one Cr(2), and one Cr(3) atom. is represented by the CIF card [CIF]
data_Na2Cr7O14
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.948
_cell_length_b   9.948
_cell_length_c   9.948
_cell_angle_alpha   33.627
_cell_angle_beta   33.627
_cell_angle_gamma   33.627
_symmetry_Int_Tables_number   1
_cell_volume   268.980
_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
  Na  Na0  1  0.302  0.302  0.302  1.0
  Na  Na1  1  0.698  0.698  0.698  1.0
  Cr  Cr2  1  0.500  0.000  0.000  1.0
  Cr  Cr3  1  0.060  0.060  0.060  1.0
  Cr  Cr4  1  0.000  0.000  0.500  1.0
  Cr  Cr5  1  0.000  0.500  0.000  1.0
  Cr  Cr6  1  0.576  0.576  0.576  1.0
  Cr  Cr7  1  0.424  0.424  0.424  1.0
  Cr  Cr8  1  0.940  0.940  0.940  1.0
  O  O9  1  0.129  0.129  0.129  1.0
  O  O10  1  0.637  0.116  0.637  1.0
  O  O11  1  0.884  0.363  0.363  1.0
  O  O12  1  0.778  0.299  0.778  1.0
  O  O13  1  0.701  0.222  0.222  1.0
  O  O14  1  0.222  0.222  0.701  1.0
  O  O15  1  0.363  0.363  0.884  1.0
  O  O16  1  0.637  0.637  0.116  1.0
  O  O17  1  0.778  0.778  0.299  1.0
  O  O18  1  0.299  0.778  0.778  1.0
  O  O19  1  0.222  0.701  0.222  1.0
  O  O20  1  0.116  0.637  0.637  1.0
  O  O21  1  0.363  0.884  0.363  1.0
  O  O22  1  0.871  0.871  0.871  1.0
[/CIF]
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