The material described by NiNb2O6 is Hydrophilite-derived structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with six equivalent Ni(1)O6 octahedra, and edges with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-51°. In the second Nb site, Nb(2) is bonded to two equivalent O(3) and four equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with six equivalent Nb(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-51°. In the third Nb site, Nb(3) is bonded to one O(1), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with three equivalent Nb(2)O6 octahedra, corners with five equivalent Ni(1)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and  an edgeedge with one Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-58°. Ni(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(5) atoms to form NiO6 octahedra that share corners with three equivalent Nb(1)O6 octahedra, corners with five equivalent Nb(3)O6 octahedra,  an edgeedge with one Nb(2)O6 octahedra, and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-58°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Nb(1), one Nb(3), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Nb(1) and two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Nb(1), one Nb(2), and one Nb(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Nb(3) and one Ni(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Nb(2), one Nb(3), and one Ni(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb2NiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.688
_cell_length_b   5.688
_cell_length_c   7.493
_cell_angle_alpha   108.224
_cell_angle_beta   108.224
_cell_angle_gamma   72.009
_symmetry_Int_Tables_number   1
_cell_volume   212.643
_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  0.667  0.667  0.167  1.0
  Nb  Nb1  1  0.667  0.667  0.667  1.0
  Nb  Nb2  1  0.012  0.012  0.483  1.0
  Nb  Nb3  1  0.322  0.322  0.851  1.0
  Ni  Ni4  1  0.325  0.325  0.329  1.0
  Ni  Ni5  1  0.008  0.008  0.004  1.0
  O  O6  1  0.433  0.433  0.127  1.0
  O  O7  1  0.900  0.900  0.206  1.0
  O  O8  1  0.376  0.958  0.167  1.0
  O  O9  1  0.958  0.376  0.167  1.0
  O  O10  1  0.771  0.771  0.467  1.0
  O  O11  1  0.562  0.562  0.866  1.0
  O  O12  1  0.100  0.100  0.791  1.0
  O  O13  1  0.233  0.233  0.542  1.0
  O  O14  1  0.309  0.709  0.508  1.0
  O  O15  1  0.709  0.309  0.508  1.0
  O  O16  1  0.025  0.625  0.826  1.0
  O  O17  1  0.625  0.025  0.826  1.0
[/CIF]
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The material described by NiNb2O6 is Hydrophilite-derived structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra, corners with six equivalent Ni(1)O6 octahedra, and edges with two equivalent Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-51°. In the second Nb site, Nb(2) is bonded to two equivalent O(3) and four equivalent O(5) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with six equivalent Nb(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-51°. In the third Nb site, Nb(3) is bonded to one O(1), one O(3), two equivalent O(4), and two equivalent O(5) atoms to form NbO6 octahedra that share corners with three equivalent Nb(2)O6 octahedra, corners with five equivalent Ni(1)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and  an edgeedge with one Nb(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-58°. Ni(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(5) atoms to form NiO6 octahedra that share corners with three equivalent Nb(1)O6 octahedra, corners with five equivalent Nb(3)O6 octahedra,  an edgeedge with one Nb(2)O6 octahedra, and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-58°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Nb(1), one Nb(3), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Nb(1) and two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Nb(1), one Nb(2), and one Nb(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Nb(3) and one Ni(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Nb(2), one Nb(3), and one Ni(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nb2NiO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.688
_cell_length_b   5.688
_cell_length_c   7.493
_cell_angle_alpha   108.224
_cell_angle_beta   108.224
_cell_angle_gamma   72.009
_symmetry_Int_Tables_number   1
_cell_volume   212.643
_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  0.667  0.667  0.167  1.0
  Nb  Nb1  1  0.667  0.667  0.667  1.0
  Nb  Nb2  1  0.012  0.012  0.483  1.0
  Nb  Nb3  1  0.322  0.322  0.851  1.0
  Ni  Ni4  1  0.325  0.325  0.329  1.0
  Ni  Ni5  1  0.008  0.008  0.004  1.0
  O  O6  1  0.433  0.433  0.127  1.0
  O  O7  1  0.900  0.900  0.206  1.0
  O  O8  1  0.376  0.958  0.167  1.0
  O  O9  1  0.958  0.376  0.167  1.0
  O  O10  1  0.771  0.771  0.467  1.0
  O  O11  1  0.562  0.562  0.866  1.0
  O  O12  1  0.100  0.100  0.791  1.0
  O  O13  1  0.233  0.233  0.542  1.0
  O  O14  1  0.309  0.709  0.508  1.0
  O  O15  1  0.709  0.309  0.508  1.0
  O  O16  1  0.025  0.625  0.826  1.0
  O  O17  1  0.625  0.025  0.826  1.0
[/CIF]
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