The crystal structure described by Nb2CrZn2O8 crystallizes in the monoclinic Cc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(3), one O(7), two equivalent O(1), and two equivalent O(5) atoms to form distorted NbO6 octahedra that share corners with four equivalent Cr(1)O6 octahedra and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-55°. In the second Nb site, Nb(2) is bonded to one O(4), one O(8), two equivalent O(2), and two equivalent O(6) atoms to form distorted NbO6 octahedra that share corners with four equivalent Cr(1)O6 octahedra and edges with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. Cr(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a distorted see-saw-like geometry to one O(6), one O(7), and two equivalent O(8) atoms. In the second Zn site, Zn(2) is bonded in a distorted see-saw-like geometry to one O(5), one O(8), and two equivalent O(7) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Nb(1) and one Cr(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Nb(2) and one Cr(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Cr(1) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Nb(1) and one Zn(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Nb(2) and one Zn(1) atom. In the seventh O site, O(7) is bonded to one Nb(1), one Zn(1), and two equivalent Zn(2) atoms to form a mixture of edge and corner-sharing ONbZn3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Nb(2), one Zn(2), and two equivalent Zn(1) atoms to form a mixture of edge and corner-sharing ONbZn3 trigonal pyramids. is represented by the CIF card [CIF]
data_Nb2Zn2CrO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.230
_cell_length_b   10.230
_cell_length_c   5.287
_cell_angle_alpha   89.192
_cell_angle_beta   89.192
_cell_angle_gamma   34.085
_symmetry_Int_Tables_number   1
_cell_volume   310.049
_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
  Nb  Nb0  1  0.044  0.723  0.732  1.0
  Nb  Nb1  1  0.274  0.956  0.760  1.0
  Nb  Nb2  1  0.956  0.274  0.260  1.0
  Nb  Nb3  1  0.723  0.044  0.232  1.0
  Zn  Zn4  1  0.875  0.562  0.762  1.0
  Zn  Zn5  1  0.433  0.125  0.735  1.0
  Zn  Zn6  1  0.125  0.433  0.235  1.0
  Zn  Zn7  1  0.562  0.875  0.262  1.0
  Cr  Cr8  1  0.649  0.350  0.757  1.0
  Cr  Cr9  1  0.350  0.649  0.257  1.0
  O  O10  1  0.035  0.819  0.064  1.0
  O  O11  1  0.191  0.948  0.427  1.0
  O  O12  1  0.948  0.191  0.927  1.0
  O  O13  1  0.819  0.035  0.564  1.0
  O  O14  1  0.320  0.565  0.593  1.0
  O  O15  1  0.416  0.699  0.926  1.0
  O  O16  1  0.699  0.416  0.426  1.0
  O  O17  1  0.565  0.320  0.093  1.0
  O  O18  1  0.925  0.714  0.435  1.0
  O  O19  1  0.282  0.074  0.062  1.0
  O  O20  1  0.451  0.158  0.363  1.0
  O  O21  1  0.838  0.548  0.135  1.0
  O  O22  1  0.548  0.838  0.635  1.0
  O  O23  1  0.158  0.451  0.863  1.0
  O  O24  1  0.714  0.925  0.935  1.0
  O  O25  1  0.074  0.282  0.562  1.0
[/CIF]
.
The crystal structure described by Nb2CrZn2O8 crystallizes in the monoclinic Cc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(3), one O(7), two equivalent O(1), and two equivalent O(5) atoms to form distorted NbO6 octahedra that share corners with four equivalent Cr(1)O6 octahedra and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-55°. In the second Nb site, Nb(2) is bonded to one O(4), one O(8), two equivalent O(2), and two equivalent O(6) atoms to form distorted NbO6 octahedra that share corners with four equivalent Cr(1)O6 octahedra and edges with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-54°. Cr(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-55°. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a distorted see-saw-like geometry to one O(6), one O(7), and two equivalent O(8) atoms. In the second Zn site, Zn(2) is bonded in a distorted see-saw-like geometry to one O(5), one O(8), and two equivalent O(7) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Nb(1) and one Cr(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Nb(2) and one Cr(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Nb(1) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Nb(2) and two equivalent Cr(1) atoms. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Nb(1) and one Zn(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Nb(2) and one Zn(1) atom. In the seventh O site, O(7) is bonded to one Nb(1), one Zn(1), and two equivalent Zn(2) atoms to form a mixture of edge and corner-sharing ONbZn3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Nb(2), one Zn(2), and two equivalent Zn(1) atoms to form a mixture of edge and corner-sharing ONbZn3 trigonal pyramids. is represented by the CIF card [CIF]
data_Nb2Zn2CrO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.230
_cell_length_b   10.230
_cell_length_c   5.287
_cell_angle_alpha   89.192
_cell_angle_beta   89.192
_cell_angle_gamma   34.085
_symmetry_Int_Tables_number   1
_cell_volume   310.049
_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
  Nb  Nb0  1  0.044  0.723  0.732  1.0
  Nb  Nb1  1  0.274  0.956  0.760  1.0
  Nb  Nb2  1  0.956  0.274  0.260  1.0
  Nb  Nb3  1  0.723  0.044  0.232  1.0
  Zn  Zn4  1  0.875  0.562  0.762  1.0
  Zn  Zn5  1  0.433  0.125  0.735  1.0
  Zn  Zn6  1  0.125  0.433  0.235  1.0
  Zn  Zn7  1  0.562  0.875  0.262  1.0
  Cr  Cr8  1  0.649  0.350  0.757  1.0
  Cr  Cr9  1  0.350  0.649  0.257  1.0
  O  O10  1  0.035  0.819  0.064  1.0
  O  O11  1  0.191  0.948  0.427  1.0
  O  O12  1  0.948  0.191  0.927  1.0
  O  O13  1  0.819  0.035  0.564  1.0
  O  O14  1  0.320  0.565  0.593  1.0
  O  O15  1  0.416  0.699  0.926  1.0
  O  O16  1  0.699  0.416  0.426  1.0
  O  O17  1  0.565  0.320  0.093  1.0
  O  O18  1  0.925  0.714  0.435  1.0
  O  O19  1  0.282  0.074  0.062  1.0
  O  O20  1  0.451  0.158  0.363  1.0
  O  O21  1  0.838  0.548  0.135  1.0
  O  O22  1  0.548  0.838  0.635  1.0
  O  O23  1  0.158  0.451  0.863  1.0
  O  O24  1  0.714  0.925  0.935  1.0
  O  O25  1  0.074  0.282  0.562  1.0
[/CIF]
.