The structure described by NaCr6O11 crystallizes in the monoclinic Cc space group. Na(1) is bonded to one O(10), one O(11), one O(2), one O(3), one O(7), one O(8), two equivalent O(1), two equivalent O(6), and two equivalent O(9) atoms to form distorted NaO12 cuboctahedra that share corners with six equivalent Na(1)O12 cuboctahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(5)O6 octahedra, edges with two equivalent Cr(6)O6 octahedra, edges with three equivalent Cr(2)O5 trigonal bipyramids, faces with three equivalent Cr(3)O6 octahedra, and faces with three equivalent Cr(4)O6 octahedra. There are six inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form CrO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with two equivalent Cr(4)O6 octahedra, corners with two equivalent Cr(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O12 cuboctahedra, edges with two equivalent Cr(5)O6 octahedra, and edges with two equivalent Cr(6)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the second Cr site, Cr(2) is bonded to one O(1), one O(4), one O(5), one O(6), and one O(9) atom to form CrO5 trigonal bipyramids that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(5)O6 octahedra, corners with two equivalent Cr(6)O6 octahedra, corners with three equivalent Cr(3)O6 octahedra, corners with three equivalent Cr(4)O6 octahedra, and edges with three equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 41-56°. In the third Cr site, Cr(3) is bonded to one O(1), one O(10), one O(3), one O(6), one O(8), and one O(9) atom to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(5)O6 octahedra, corners with two equivalent Cr(6)O6 octahedra, corners with three equivalent Cr(2)O5 trigonal bipyramids, faces with three equivalent Na(1)O12 cuboctahedra, and  a faceface with one Cr(4)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the fourth Cr site, Cr(4) is bonded to one O(1), one O(11), one O(2), one O(6), one O(7), and one O(9) atom to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(5)O6 octahedra, corners with two equivalent Cr(6)O6 octahedra, corners with three equivalent Cr(2)O5 trigonal bipyramids, faces with three equivalent Na(1)O12 cuboctahedra, and  a faceface with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the fifth Cr site, Cr(5) is bonded to one O(10), one O(11), one O(3), one O(4), one O(5), and one O(7) atom to form CrO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with two equivalent Cr(4)O6 octahedra, corners with two equivalent Cr(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O12 cuboctahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(6)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the sixth Cr site, Cr(6) is bonded to one O(10), one O(11), one O(2), one O(4), one O(5), and one O(8) atom to form CrO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with two equivalent Cr(4)O6 octahedra, corners with two equivalent Cr(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O12 cuboctahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(5)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are eleven inequivalent O sites. In the first O site, O(5) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Cr(2), one Cr(5), and one Cr(6) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Na(1), one Cr(2), one Cr(3), and one Cr(4) atom. In the third O site, O(7) is bonded in a 4-coordinate geometry to one Na(1), one Cr(1), one Cr(4), and one Cr(5) atom. In the fourth O site, O(8) is bonded in a 3-coordinate geometry to one Na(1), one Cr(1), one Cr(3), and one Cr(6) atom. In the fifth O site, O(9) is bonded in a 3-coordinate geometry to two equivalent Na(1), one Cr(2), one Cr(3), and one Cr(4) atom. In the sixth O site, O(10) is bonded in a 3-coordinate geometry to one Na(1), one Cr(3), one Cr(5), and one Cr(6) atom. In the seventh O site, O(11) is bonded in a 4-coordinate geometry to one Na(1), one Cr(4), one Cr(5), and one Cr(6) atom. In the eighth O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Na(1), one Cr(2), one Cr(3), and one Cr(4) atom. In the ninth O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Cr(1), one Cr(4), and one Cr(6) atom. In the tenth O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), one Cr(1), one Cr(3), and one Cr(5) atom. In the eleventh O site, O(4) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Cr(2), one Cr(5), and one Cr(6) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaCr6O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.825
_cell_length_b   5.823
_cell_length_c   13.000
_cell_angle_alpha   89.933
_cell_angle_beta   90.034
_cell_angle_gamma   119.993
_symmetry_Int_Tables_number   1
_cell_volume   381.911
_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
  Na  Na0  1  0.332  0.666  0.254  1.0
  Na  Na1  1  0.668  0.334  0.754  1.0
  Cr  Cr2  1  0.000  0.500  0.000  1.0
  Cr  Cr3  1  0.334  0.667  0.750  1.0
  Cr  Cr4  1  1.000  0.000  0.146  1.0
  Cr  Cr5  1  1.000  1.000  0.355  1.0
  Cr  Cr6  1  0.000  0.000  0.646  1.0
  Cr  Cr7  1  0.000  1.000  0.855  1.0
  Cr  Cr8  1  0.500  1.000  0.000  1.0
  Cr  Cr9  1  0.500  0.500  0.000  1.0
  Cr  Cr10  1  0.500  0.500  0.500  1.0
  Cr  Cr11  1  0.666  0.333  0.250  1.0
  Cr  Cr12  1  0.500  1.000  0.500  1.0
  Cr  Cr13  1  1.000  0.500  0.500  1.0
  O  O14  1  0.154  0.847  0.750  1.0
  O  O15  1  0.173  0.825  0.422  1.0
  O  O16  1  0.175  0.825  0.079  1.0
  O  O17  1  0.333  0.667  0.913  1.0
  O  O18  1  0.333  0.667  0.588  1.0
  O  O19  1  0.154  0.306  0.750  1.0
  O  O20  1  0.175  0.350  0.422  1.0
  O  O21  1  0.173  0.348  0.078  1.0
  O  O22  1  0.306  0.153  0.250  1.0
  O  O23  1  0.652  0.827  0.078  1.0
  O  O24  1  0.651  0.825  0.423  1.0
  O  O25  1  0.349  0.173  0.923  1.0
  O  O26  1  0.348  0.175  0.578  1.0
  O  O27  1  0.694  0.847  0.750  1.0
  O  O28  1  0.846  0.694  0.250  1.0
  O  O29  1  0.667  0.333  0.088  1.0
  O  O30  1  0.825  0.651  0.579  1.0
  O  O31  1  0.667  0.333  0.413  1.0
  O  O32  1  0.827  0.651  0.922  1.0
  O  O33  1  0.827  0.175  0.578  1.0
  O  O34  1  0.825  0.175  0.922  1.0
  O  O35  1  0.846  0.153  0.250  1.0
[/CIF]
.
The structure described by NaCr6O11 crystallizes in the monoclinic Cc space group. Na(1) is bonded to one O(10), one O(11), one O(2), one O(3), one O(7), one O(8), two equivalent O(1), two equivalent O(6), and two equivalent O(9) atoms to form distorted NaO12 cuboctahedra that share corners with six equivalent Na(1)O12 cuboctahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(5)O6 octahedra, edges with two equivalent Cr(6)O6 octahedra, edges with three equivalent Cr(2)O5 trigonal bipyramids, faces with three equivalent Cr(3)O6 octahedra, and faces with three equivalent Cr(4)O6 octahedra. There are six inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form CrO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with two equivalent Cr(4)O6 octahedra, corners with two equivalent Cr(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O12 cuboctahedra, edges with two equivalent Cr(5)O6 octahedra, and edges with two equivalent Cr(6)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the second Cr site, Cr(2) is bonded to one O(1), one O(4), one O(5), one O(6), and one O(9) atom to form CrO5 trigonal bipyramids that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(5)O6 octahedra, corners with two equivalent Cr(6)O6 octahedra, corners with three equivalent Cr(3)O6 octahedra, corners with three equivalent Cr(4)O6 octahedra, and edges with three equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 41-56°. In the third Cr site, Cr(3) is bonded to one O(1), one O(10), one O(3), one O(6), one O(8), and one O(9) atom to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(5)O6 octahedra, corners with two equivalent Cr(6)O6 octahedra, corners with three equivalent Cr(2)O5 trigonal bipyramids, faces with three equivalent Na(1)O12 cuboctahedra, and  a faceface with one Cr(4)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the fourth Cr site, Cr(4) is bonded to one O(1), one O(11), one O(2), one O(6), one O(7), and one O(9) atom to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(5)O6 octahedra, corners with two equivalent Cr(6)O6 octahedra, corners with three equivalent Cr(2)O5 trigonal bipyramids, faces with three equivalent Na(1)O12 cuboctahedra, and  a faceface with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the fifth Cr site, Cr(5) is bonded to one O(10), one O(11), one O(3), one O(4), one O(5), and one O(7) atom to form CrO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with two equivalent Cr(4)O6 octahedra, corners with two equivalent Cr(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O12 cuboctahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(6)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the sixth Cr site, Cr(6) is bonded to one O(10), one O(11), one O(2), one O(4), one O(5), and one O(8) atom to form CrO6 octahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with two equivalent Cr(4)O6 octahedra, corners with two equivalent Cr(2)O5 trigonal bipyramids, edges with two equivalent Na(1)O12 cuboctahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with two equivalent Cr(5)O6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are eleven inequivalent O sites. In the first O site, O(5) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Cr(2), one Cr(5), and one Cr(6) atom. In the second O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Na(1), one Cr(2), one Cr(3), and one Cr(4) atom. In the third O site, O(7) is bonded in a 4-coordinate geometry to one Na(1), one Cr(1), one Cr(4), and one Cr(5) atom. In the fourth O site, O(8) is bonded in a 3-coordinate geometry to one Na(1), one Cr(1), one Cr(3), and one Cr(6) atom. In the fifth O site, O(9) is bonded in a 3-coordinate geometry to two equivalent Na(1), one Cr(2), one Cr(3), and one Cr(4) atom. In the sixth O site, O(10) is bonded in a 3-coordinate geometry to one Na(1), one Cr(3), one Cr(5), and one Cr(6) atom. In the seventh O site, O(11) is bonded in a 4-coordinate geometry to one Na(1), one Cr(4), one Cr(5), and one Cr(6) atom. In the eighth O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Na(1), one Cr(2), one Cr(3), and one Cr(4) atom. In the ninth O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Cr(1), one Cr(4), and one Cr(6) atom. In the tenth O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), one Cr(1), one Cr(3), and one Cr(5) atom. In the eleventh O site, O(4) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Cr(2), one Cr(5), and one Cr(6) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaCr6O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.825
_cell_length_b   5.823
_cell_length_c   13.000
_cell_angle_alpha   89.933
_cell_angle_beta   90.034
_cell_angle_gamma   119.993
_symmetry_Int_Tables_number   1
_cell_volume   381.911
_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
  Na  Na0  1  0.332  0.666  0.254  1.0
  Na  Na1  1  0.668  0.334  0.754  1.0
  Cr  Cr2  1  0.000  0.500  0.000  1.0
  Cr  Cr3  1  0.334  0.667  0.750  1.0
  Cr  Cr4  1  1.000  0.000  0.146  1.0
  Cr  Cr5  1  1.000  1.000  0.355  1.0
  Cr  Cr6  1  0.000  0.000  0.646  1.0
  Cr  Cr7  1  0.000  1.000  0.855  1.0
  Cr  Cr8  1  0.500  1.000  0.000  1.0
  Cr  Cr9  1  0.500  0.500  0.000  1.0
  Cr  Cr10  1  0.500  0.500  0.500  1.0
  Cr  Cr11  1  0.666  0.333  0.250  1.0
  Cr  Cr12  1  0.500  1.000  0.500  1.0
  Cr  Cr13  1  1.000  0.500  0.500  1.0
  O  O14  1  0.154  0.847  0.750  1.0
  O  O15  1  0.173  0.825  0.422  1.0
  O  O16  1  0.175  0.825  0.079  1.0
  O  O17  1  0.333  0.667  0.913  1.0
  O  O18  1  0.333  0.667  0.588  1.0
  O  O19  1  0.154  0.306  0.750  1.0
  O  O20  1  0.175  0.350  0.422  1.0
  O  O21  1  0.173  0.348  0.078  1.0
  O  O22  1  0.306  0.153  0.250  1.0
  O  O23  1  0.652  0.827  0.078  1.0
  O  O24  1  0.651  0.825  0.423  1.0
  O  O25  1  0.349  0.173  0.923  1.0
  O  O26  1  0.348  0.175  0.578  1.0
  O  O27  1  0.694  0.847  0.750  1.0
  O  O28  1  0.846  0.694  0.250  1.0
  O  O29  1  0.667  0.333  0.088  1.0
  O  O30  1  0.825  0.651  0.579  1.0
  O  O31  1  0.667  0.333  0.413  1.0
  O  O32  1  0.827  0.651  0.922  1.0
  O  O33  1  0.827  0.175  0.578  1.0
  O  O34  1  0.825  0.175  0.922  1.0
  O  O35  1  0.846  0.153  0.250  1.0
[/CIF]
.