The structure described by NaCr(SO4)2 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a distorted hexagonal planar geometry to two equivalent O(1) and four equivalent O(2) atoms. Cr(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with six equivalent S(1)O4 tetrahedra. S(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-46°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Na(1) and one S(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Cr(1), and one S(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaCr(SO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.815
_cell_length_b   4.815
_cell_length_c   7.472
_cell_angle_alpha   87.496
_cell_angle_beta   87.496
_cell_angle_gamma   65.231
_symmetry_Int_Tables_number   1
_cell_volume   157.056
_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  0.000  0.000  0.500  1.0
  Cr  Cr1  1  0.000  0.000  0.000  1.0
  S  S2  1  0.365  0.365  0.788  1.0
  S  S3  1  0.635  0.635  0.212  1.0
  O  O4  1  0.296  0.296  0.613  1.0
  O  O5  1  0.704  0.704  0.387  1.0
  O  O6  1  0.708  0.238  0.805  1.0
  O  O7  1  0.292  0.762  0.195  1.0
  O  O8  1  0.762  0.292  0.195  1.0
  O  O9  1  0.238  0.708  0.805  1.0
  O  O10  1  0.242  0.242  0.943  1.0
  O  O11  1  0.758  0.758  0.057  1.0
[/CIF]
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The structure described by NaCr(SO4)2 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a distorted hexagonal planar geometry to two equivalent O(1) and four equivalent O(2) atoms. Cr(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with six equivalent S(1)O4 tetrahedra. S(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-46°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Na(1) and one S(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Cr(1), and one S(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaCr(SO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.815
_cell_length_b   4.815
_cell_length_c   7.472
_cell_angle_alpha   87.496
_cell_angle_beta   87.496
_cell_angle_gamma   65.231
_symmetry_Int_Tables_number   1
_cell_volume   157.056
_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  0.000  0.000  0.500  1.0
  Cr  Cr1  1  0.000  0.000  0.000  1.0
  S  S2  1  0.365  0.365  0.788  1.0
  S  S3  1  0.635  0.635  0.212  1.0
  O  O4  1  0.296  0.296  0.613  1.0
  O  O5  1  0.704  0.704  0.387  1.0
  O  O6  1  0.708  0.238  0.805  1.0
  O  O7  1  0.292  0.762  0.195  1.0
  O  O8  1  0.762  0.292  0.195  1.0
  O  O9  1  0.238  0.708  0.805  1.0
  O  O10  1  0.242  0.242  0.943  1.0
  O  O11  1  0.758  0.758  0.057  1.0
[/CIF]
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