The crystal structure described by Ba3NiNb2O9 is (Cubic) Perovskite-derived structured and crystallizes in the monoclinic P2_1/m space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(8), one O(9), two equivalent O(1), two equivalent O(10), two equivalent O(13), two equivalent O(3), and two equivalent O(4) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(5)O12 cuboctahedra, corners with two equivalent Ba(2)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Ba(6)O12 cuboctahedra, corners with four equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with three equivalent Ba(6)O12 cuboctahedra,  a faceface with one Nb(3)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Ni(2)O6 octahedra, and faces with three equivalent Nb(4)O6 octahedra. In the second Ba site, Ba(2) is bonded to one O(6), one O(7), two equivalent O(1), two equivalent O(11), two equivalent O(12), two equivalent O(2), and two equivalent O(5) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(3)O12 cuboctahedra, corners with two equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Ba(5)O12 cuboctahedra, corners with three equivalent Ba(4)O12 cuboctahedra, corners with four equivalent Ba(2)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with two equivalent Ba(5)O12 cuboctahedra, faces with three equivalent Ba(4)O12 cuboctahedra,  a faceface with one Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, faces with two equivalent Ni(1)O6 octahedra, and faces with three equivalent Nb(2)O6 octahedra. In the third Ba site, Ba(3) is bonded to one O(4), one O(6), two equivalent O(1), two equivalent O(10), two equivalent O(12), two equivalent O(13), and two equivalent O(8) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(2)O12 cuboctahedra, corners with two equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with two equivalent Ba(4)O12 cuboctahedra, corners with two equivalent Ba(5)O12 cuboctahedra, corners with three equivalent Ba(6)O12 cuboctahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(6)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(5)O12 cuboctahedra,  a faceface with one Nb(4)O6 octahedra,  a faceface with one Ni(1)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with two equivalent Ni(2)O6 octahedra. In the fourth Ba site, Ba(4) is bonded to one O(5), two equivalent O(12), two equivalent O(2), three equivalent O(7), and four equivalent O(11) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Ba(2)O12 cuboctahedra, corners with three equivalent Ba(5)O12 cuboctahedra, corners with four equivalent Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra, faces with three equivalent Ba(2)O12 cuboctahedra,  a faceface with one Nb(3)O6 octahedra, faces with three equivalent Ni(1)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. In the fifth Ba site, Ba(5) is bonded to one O(5), one O(8), two equivalent O(1), two equivalent O(10), two equivalent O(11), two equivalent O(12), and two equivalent O(6) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(1)O12 cuboctahedra, corners with two equivalent Ba(2)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with two equivalent Ba(5)O12 cuboctahedra, corners with two equivalent Ba(6)O12 cuboctahedra, corners with three equivalent Ba(4)O12 cuboctahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra,  a faceface with one Nb(2)O6 octahedra,  a faceface with one Ni(2)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with two equivalent Ni(1)O6 octahedra. In the sixth Ba site, Ba(6) is bonded to one O(4), two equivalent O(10), two equivalent O(3), three equivalent O(9), and four equivalent O(13) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(5)O12 cuboctahedra, corners with three equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ba(3)O12 cuboctahedra, corners with four equivalent Ba(6)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with two equivalent Ba(6)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra,  a faceface with one Nb(1)O6 octahedra, faces with three equivalent Ni(2)O6 octahedra, and faces with four equivalent Nb(4)O6 octahedra. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(6), two equivalent O(1), and two equivalent O(10) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(6)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(5)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second Nb site, Nb(2) is bonded to one O(5), one O(7), two equivalent O(11), and two equivalent O(2) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with three equivalent Ni(1)O6 octahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with three equivalent Ba(2)O12 cuboctahedra, and faces with four equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third Nb site, Nb(3) is bonded to one O(5), one O(8), two equivalent O(1), and two equivalent O(12) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(5)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fourth Nb site, Nb(4) is bonded to one O(4), one O(9), two equivalent O(13), and two equivalent O(3) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra, corners with three equivalent Ni(2)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and faces with four equivalent Ba(6)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(6), one O(7), two equivalent O(11), and two equivalent O(12) atoms to form NiO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(5)O12 cuboctahedra, and faces with three equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. In the second Ni site, Ni(2) is bonded to one O(8), one O(9), two equivalent O(10), and two equivalent O(13) atoms to form NiO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Nb(4)O6 octahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with three equivalent Ba(6)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(5), one Nb(1), and one Nb(3) atom to form distorted OBa4Nb2 octahedra that share  a cornercorner with one O(4)Ba4Nb2 octahedra,  a cornercorner with one O(5)Ba4Nb2 octahedra,  a cornercorner with one O(9)Ba4NbNi octahedra, corners with two equivalent O(2)Ba4Nb2 octahedra, corners with two equivalent O(3)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4NbNi octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with three equivalent O(12)Ba4NbNi octahedra,  an edgeedge with one O(12)Ba4NbNi octahedra,  an edgeedge with one O(13)Ba4NbNi octahedra,  a faceface with one O(4)Ba4Nb2 octahedra,  a faceface with one O(5)Ba4Nb2 octahedra,  a faceface with one O(12)Ba4NbNi octahedra,  a faceface with one O(6)Ba4NbNi octahedra, and faces with two equivalent O(1)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the second O site, O(2) is bonded to two equivalent Ba(2), two equivalent Ba(4), and two equivalent Nb(2) atoms to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(5)Ba4Nb2 octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with four equivalent O(1)Ba4Nb2 octahedra, corners with four equivalent O(12)Ba4NbNi octahedra, edges with two equivalent O(12)Ba4NbNi octahedra, faces with two equivalent O(2)Ba4Nb2 octahedra, and faces with two equivalent O(5)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Ba(6), and two equivalent Nb(4) atoms to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(4)Ba4Nb2 octahedra, corners with four equivalent O(1)Ba4Nb2 octahedra, corners with four equivalent O(9)Ba4NbNi octahedra, corners with six equivalent O(13)Ba4NbNi octahedra, edges with two equivalent O(13)Ba4NbNi octahedra, faces with two equivalent O(3)Ba4Nb2 octahedra, faces with two equivalent O(4)Ba4Nb2 octahedra, faces with two equivalent O(13)Ba4NbNi octahedra, and faces with two equivalent O(9)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the fourth O site, O(4) is bonded to one Ba(3), one Ba(6), two equivalent Ba(1), one Nb(1), and one Nb(4) atom to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(1)Ba4Nb2 octahedra, corners with two equivalent O(3)Ba4Nb2 octahedra, corners with two equivalent O(4)Ba4Nb2 octahedra, corners with two equivalent O(12)Ba4NbNi octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with two equivalent O(9)Ba4NbNi octahedra, corners with six equivalent O(13)Ba4NbNi octahedra, edges with two equivalent O(9)Ba4NbNi octahedra, faces with two equivalent O(1)Ba4Nb2 octahedra, faces with two equivalent O(3)Ba4Nb2 octahedra, and faces with two equivalent O(13)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the fifth O site, O(5) is bonded to one Ba(4), one Ba(5), two equivalent Ba(2), one Nb(2), and one Nb(3) atom to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(1)Ba4Nb2 octahedra, corners with two equivalent O(2)Ba4Nb2 octahedra, corners with two equivalent O(5)Ba4Nb2 octahedra, corners with four equivalent O(12)Ba4NbNi octahedra, edges with two equivalent O(6)Ba4NbNi octahedra, faces with two equivalent O(1)Ba4Nb2 octahedra, faces with two equivalent O(2)Ba4Nb2 octahedra, and faces with two equivalent O(12)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the sixth O site, O(6) is bonded to one Ba(2), one Ba(3), two equivalent Ba(5), one Nb(1), and one Ni(1) atom to form distorted OBa4NbNi octahedra that share corners with two equivalent O(2)Ba4Nb2 octahedra, corners with two equivalent O(4)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4NbNi octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with four equivalent O(1)Ba4Nb2 octahedra, corners with four equivalent O(12)Ba4NbNi octahedra, edges with two equivalent O(5)Ba4Nb2 octahedra, faces with two equivalent O(1)Ba4Nb2 octahedra, and faces with two equivalent O(12)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 1-62°. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(4), one Nb(2), and one Ni(1) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to one Ba(1), one Ba(5), two equivalent Ba(3), one Nb(3), and one Ni(2) atom. In the ninth O site, O(9) is bonded to one Ba(1), three equivalent Ba(6), one Nb(4), and one Ni(2) atom to form distorted OBa4NbNi octahedra that share corners with two equivalent O(1)Ba4Nb2 octahedra, corners with two equivalent O(4)Ba4Nb2 octahedra, corners with two equivalent O(9)Ba4NbNi octahedra, corners with four equivalent O(3)Ba4Nb2 octahedra, corners with six equivalent O(13)Ba4NbNi octahedra, edges with two equivalent O(4)Ba4Nb2 octahedra, edges with two equivalent O(9)Ba4NbNi octahedra, faces with two equivalent O(3)Ba4Nb2 octahedra, and faces with four equivalent O(13)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 1-62°. In the tenth O site, O(10) is bonded in a distorted linear geometry to one Ba(1), one Ba(3), one Ba(5), one Ba(6), one Nb(1), and one Ni(2) atom. In the eleventh O site, O(11) is bonded in a distorted linear geometry to one Ba(2), one Ba(5), two equivalent Ba(4), one Nb(2), and one Ni(1) atom. In the twelfth O site, O(12) is bonded to one Ba(2), one Ba(3), one Ba(4), one Ba(5), one Nb(3), and one Ni(1) atom to form distorted OBa4NbNi octahedra that share  a cornercorner with one O(4)Ba4Nb2 octahedra, corners with two equivalent O(2)Ba4Nb2 octahedra, corners with two equivalent O(5)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4NbNi octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with three equivalent O(1)Ba4Nb2 octahedra,  an edgeedge with one O(1)Ba4Nb2 octahedra,  an edgeedge with one O(2)Ba4Nb2 octahedra,  a faceface with one O(1)Ba4Nb2 octahedra,  a faceface with one O(5)Ba4Nb2 octahedra,  a faceface with one O(6)Ba4NbNi octahedra, and faces with two equivalent O(12)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 1-62°. In the thirteenth O site, O(13) is bonded to one Ba(1), one Ba(3), two equivalent Ba(6), one Nb(4), and one Ni(2) atom to form distorted OBa4NbNi octahedra that share  a cornercorner with one O(6)Ba4NbNi octahedra, corners with two equivalent O(1)Ba4Nb2 octahedra, corners with two equivalent O(12)Ba4NbNi octahedra, corners with two equivalent O(13)Ba4NbNi octahedra, corners with three equivalent O(3)Ba4Nb2 octahedra, corners with three equivalent O(4)Ba4Nb2 octahedra, corners with three equivalent O(9)Ba4NbNi octahedra,  an edgeedge with one O(1)Ba4Nb2 octahedra,  an edgeedge with one O(3)Ba4Nb2 octahedra,  an edgeedge with one O(13)Ba4NbNi octahedra,  a faceface with one O(3)Ba4Nb2 octahedra,  a faceface with one O(4)Ba4Nb2 octahedra, faces with two equivalent O(13)Ba4NbNi octahedra, and faces with two equivalent O(9)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 1-62°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3Nb2NiO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.845
_cell_length_b   5.845
_cell_length_c   7.180
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   59.998
_symmetry_Int_Tables_number   1
_cell_volume   212.406
_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
  Ba  Ba0  1  0.000  1.000  0.000  1.0
  Ba  Ba1  1  0.667  0.667  0.665  1.0
  Ba  Ba2  1  0.333  0.333  0.335  1.0
  Nb  Nb3  1  0.667  0.667  0.179  1.0
  Nb  Nb4  1  0.333  0.333  0.821  1.0
  Ni  Ni5  1  1.000  0.000  0.500  1.0
  O  O6  1  0.500  1.000  1.000  1.0
  O  O7  1  0.500  0.500  1.000  1.0
  O  O8  1  0.000  0.500  0.000  1.0
  O  O9  1  0.342  0.829  0.326  1.0
  O  O10  1  0.658  0.171  0.674  1.0
  O  O11  1  0.829  0.342  0.326  1.0
  O  O12  1  0.171  0.658  0.674  1.0
  O  O13  1  0.829  0.829  0.326  1.0
  O  O14  1  0.171  0.171  0.674  1.0
[/CIF]
.
The crystal structure described by Ba3NiNb2O9 is (Cubic) Perovskite-derived structured and crystallizes in the monoclinic P2_1/m space group. There are six inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to one O(8), one O(9), two equivalent O(1), two equivalent O(10), two equivalent O(13), two equivalent O(3), and two equivalent O(4) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(5)O12 cuboctahedra, corners with two equivalent Ba(2)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Ba(6)O12 cuboctahedra, corners with four equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, faces with three equivalent Ba(6)O12 cuboctahedra,  a faceface with one Nb(3)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Ni(2)O6 octahedra, and faces with three equivalent Nb(4)O6 octahedra. In the second Ba site, Ba(2) is bonded to one O(6), one O(7), two equivalent O(1), two equivalent O(11), two equivalent O(12), two equivalent O(2), and two equivalent O(5) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(3)O12 cuboctahedra, corners with two equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Ba(5)O12 cuboctahedra, corners with three equivalent Ba(4)O12 cuboctahedra, corners with four equivalent Ba(2)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with two equivalent Ba(5)O12 cuboctahedra, faces with three equivalent Ba(4)O12 cuboctahedra,  a faceface with one Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, faces with two equivalent Ni(1)O6 octahedra, and faces with three equivalent Nb(2)O6 octahedra. In the third Ba site, Ba(3) is bonded to one O(4), one O(6), two equivalent O(1), two equivalent O(10), two equivalent O(12), two equivalent O(13), and two equivalent O(8) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(2)O12 cuboctahedra, corners with two equivalent Ba(1)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with two equivalent Ba(4)O12 cuboctahedra, corners with two equivalent Ba(5)O12 cuboctahedra, corners with three equivalent Ba(6)O12 cuboctahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(6)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(5)O12 cuboctahedra,  a faceface with one Nb(4)O6 octahedra,  a faceface with one Ni(1)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with two equivalent Ni(2)O6 octahedra. In the fourth Ba site, Ba(4) is bonded to one O(5), two equivalent O(12), two equivalent O(2), three equivalent O(7), and four equivalent O(11) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(3)O12 cuboctahedra, corners with three equivalent Ba(2)O12 cuboctahedra, corners with three equivalent Ba(5)O12 cuboctahedra, corners with four equivalent Ba(4)O12 cuboctahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(4)O12 cuboctahedra, faces with three equivalent Ba(2)O12 cuboctahedra,  a faceface with one Nb(3)O6 octahedra, faces with three equivalent Ni(1)O6 octahedra, and faces with four equivalent Nb(2)O6 octahedra. In the fifth Ba site, Ba(5) is bonded to one O(5), one O(8), two equivalent O(1), two equivalent O(10), two equivalent O(11), two equivalent O(12), and two equivalent O(6) atoms to form BaO12 cuboctahedra that share  a cornercorner with one Ba(1)O12 cuboctahedra, corners with two equivalent Ba(2)O12 cuboctahedra, corners with two equivalent Ba(3)O12 cuboctahedra, corners with two equivalent Ba(5)O12 cuboctahedra, corners with two equivalent Ba(6)O12 cuboctahedra, corners with three equivalent Ba(4)O12 cuboctahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra,  a faceface with one Nb(2)O6 octahedra,  a faceface with one Ni(2)O6 octahedra, faces with two equivalent Nb(1)O6 octahedra, faces with two equivalent Nb(3)O6 octahedra, and faces with two equivalent Ni(1)O6 octahedra. In the sixth Ba site, Ba(6) is bonded to one O(4), two equivalent O(10), two equivalent O(3), three equivalent O(9), and four equivalent O(13) atoms to form BaO12 cuboctahedra that share corners with two equivalent Ba(5)O12 cuboctahedra, corners with three equivalent Ba(1)O12 cuboctahedra, corners with three equivalent Ba(3)O12 cuboctahedra, corners with four equivalent Ba(6)O12 cuboctahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with two equivalent Ba(6)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra,  a faceface with one Nb(1)O6 octahedra, faces with three equivalent Ni(2)O6 octahedra, and faces with four equivalent Nb(4)O6 octahedra. There are four inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(4), one O(6), two equivalent O(1), and two equivalent O(10) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(4)O6 octahedra,  a cornercorner with one Ni(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra,  a faceface with one Ba(2)O12 cuboctahedra,  a faceface with one Ba(6)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(5)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second Nb site, Nb(2) is bonded to one O(5), one O(7), two equivalent O(11), and two equivalent O(2) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with three equivalent Ni(1)O6 octahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with three equivalent Ba(2)O12 cuboctahedra, and faces with four equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third Nb site, Nb(3) is bonded to one O(5), one O(8), two equivalent O(1), and two equivalent O(12) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(2)O6 octahedra,  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra,  a faceface with one Ba(1)O12 cuboctahedra,  a faceface with one Ba(4)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with two equivalent Ba(5)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fourth Nb site, Nb(4) is bonded to one O(4), one O(9), two equivalent O(13), and two equivalent O(3) atoms to form NbO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(4)O6 octahedra, corners with three equivalent Ni(2)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with three equivalent Ba(1)O12 cuboctahedra, and faces with four equivalent Ba(6)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(6), one O(7), two equivalent O(11), and two equivalent O(12) atoms to form NiO6 octahedra that share  a cornercorner with one Nb(1)O6 octahedra, corners with two equivalent Nb(3)O6 octahedra, corners with three equivalent Nb(2)O6 octahedra,  a faceface with one Ba(3)O12 cuboctahedra, faces with two equivalent Ba(2)O12 cuboctahedra, faces with two equivalent Ba(5)O12 cuboctahedra, and faces with three equivalent Ba(4)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. In the second Ni site, Ni(2) is bonded to one O(8), one O(9), two equivalent O(10), and two equivalent O(13) atoms to form NiO6 octahedra that share  a cornercorner with one Nb(3)O6 octahedra, corners with two equivalent Nb(1)O6 octahedra, corners with three equivalent Nb(4)O6 octahedra,  a faceface with one Ba(5)O12 cuboctahedra, faces with two equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Ba(3)O12 cuboctahedra, and faces with three equivalent Ba(6)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded to one Ba(1), one Ba(2), one Ba(3), one Ba(5), one Nb(1), and one Nb(3) atom to form distorted OBa4Nb2 octahedra that share  a cornercorner with one O(4)Ba4Nb2 octahedra,  a cornercorner with one O(5)Ba4Nb2 octahedra,  a cornercorner with one O(9)Ba4NbNi octahedra, corners with two equivalent O(2)Ba4Nb2 octahedra, corners with two equivalent O(3)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4NbNi octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with three equivalent O(12)Ba4NbNi octahedra,  an edgeedge with one O(12)Ba4NbNi octahedra,  an edgeedge with one O(13)Ba4NbNi octahedra,  a faceface with one O(4)Ba4Nb2 octahedra,  a faceface with one O(5)Ba4Nb2 octahedra,  a faceface with one O(12)Ba4NbNi octahedra,  a faceface with one O(6)Ba4NbNi octahedra, and faces with two equivalent O(1)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the second O site, O(2) is bonded to two equivalent Ba(2), two equivalent Ba(4), and two equivalent Nb(2) atoms to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(5)Ba4Nb2 octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with four equivalent O(1)Ba4Nb2 octahedra, corners with four equivalent O(12)Ba4NbNi octahedra, edges with two equivalent O(12)Ba4NbNi octahedra, faces with two equivalent O(2)Ba4Nb2 octahedra, and faces with two equivalent O(5)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Ba(6), and two equivalent Nb(4) atoms to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(4)Ba4Nb2 octahedra, corners with four equivalent O(1)Ba4Nb2 octahedra, corners with four equivalent O(9)Ba4NbNi octahedra, corners with six equivalent O(13)Ba4NbNi octahedra, edges with two equivalent O(13)Ba4NbNi octahedra, faces with two equivalent O(3)Ba4Nb2 octahedra, faces with two equivalent O(4)Ba4Nb2 octahedra, faces with two equivalent O(13)Ba4NbNi octahedra, and faces with two equivalent O(9)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the fourth O site, O(4) is bonded to one Ba(3), one Ba(6), two equivalent Ba(1), one Nb(1), and one Nb(4) atom to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(1)Ba4Nb2 octahedra, corners with two equivalent O(3)Ba4Nb2 octahedra, corners with two equivalent O(4)Ba4Nb2 octahedra, corners with two equivalent O(12)Ba4NbNi octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with two equivalent O(9)Ba4NbNi octahedra, corners with six equivalent O(13)Ba4NbNi octahedra, edges with two equivalent O(9)Ba4NbNi octahedra, faces with two equivalent O(1)Ba4Nb2 octahedra, faces with two equivalent O(3)Ba4Nb2 octahedra, and faces with two equivalent O(13)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 0-62°. In the fifth O site, O(5) is bonded to one Ba(4), one Ba(5), two equivalent Ba(2), one Nb(2), and one Nb(3) atom to form distorted OBa4Nb2 octahedra that share corners with two equivalent O(1)Ba4Nb2 octahedra, corners with two equivalent O(2)Ba4Nb2 octahedra, corners with two equivalent O(5)Ba4Nb2 octahedra, corners with four equivalent O(12)Ba4NbNi octahedra, edges with two equivalent O(6)Ba4NbNi octahedra, faces with two equivalent O(1)Ba4Nb2 octahedra, faces with two equivalent O(2)Ba4Nb2 octahedra, and faces with two equivalent O(12)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the sixth O site, O(6) is bonded to one Ba(2), one Ba(3), two equivalent Ba(5), one Nb(1), and one Ni(1) atom to form distorted OBa4NbNi octahedra that share corners with two equivalent O(2)Ba4Nb2 octahedra, corners with two equivalent O(4)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4NbNi octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with four equivalent O(1)Ba4Nb2 octahedra, corners with four equivalent O(12)Ba4NbNi octahedra, edges with two equivalent O(5)Ba4Nb2 octahedra, faces with two equivalent O(1)Ba4Nb2 octahedra, and faces with two equivalent O(12)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 1-62°. In the seventh O site, O(7) is bonded in a distorted linear geometry to one Ba(2), three equivalent Ba(4), one Nb(2), and one Ni(1) atom. In the eighth O site, O(8) is bonded in a distorted linear geometry to one Ba(1), one Ba(5), two equivalent Ba(3), one Nb(3), and one Ni(2) atom. In the ninth O site, O(9) is bonded to one Ba(1), three equivalent Ba(6), one Nb(4), and one Ni(2) atom to form distorted OBa4NbNi octahedra that share corners with two equivalent O(1)Ba4Nb2 octahedra, corners with two equivalent O(4)Ba4Nb2 octahedra, corners with two equivalent O(9)Ba4NbNi octahedra, corners with four equivalent O(3)Ba4Nb2 octahedra, corners with six equivalent O(13)Ba4NbNi octahedra, edges with two equivalent O(4)Ba4Nb2 octahedra, edges with two equivalent O(9)Ba4NbNi octahedra, faces with two equivalent O(3)Ba4Nb2 octahedra, and faces with four equivalent O(13)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 1-62°. In the tenth O site, O(10) is bonded in a distorted linear geometry to one Ba(1), one Ba(3), one Ba(5), one Ba(6), one Nb(1), and one Ni(2) atom. In the eleventh O site, O(11) is bonded in a distorted linear geometry to one Ba(2), one Ba(5), two equivalent Ba(4), one Nb(2), and one Ni(1) atom. In the twelfth O site, O(12) is bonded to one Ba(2), one Ba(3), one Ba(4), one Ba(5), one Nb(3), and one Ni(1) atom to form distorted OBa4NbNi octahedra that share  a cornercorner with one O(4)Ba4Nb2 octahedra, corners with two equivalent O(2)Ba4Nb2 octahedra, corners with two equivalent O(5)Ba4Nb2 octahedra, corners with two equivalent O(13)Ba4NbNi octahedra, corners with two equivalent O(6)Ba4NbNi octahedra, corners with three equivalent O(1)Ba4Nb2 octahedra,  an edgeedge with one O(1)Ba4Nb2 octahedra,  an edgeedge with one O(2)Ba4Nb2 octahedra,  a faceface with one O(1)Ba4Nb2 octahedra,  a faceface with one O(5)Ba4Nb2 octahedra,  a faceface with one O(6)Ba4NbNi octahedra, and faces with two equivalent O(12)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 1-62°. In the thirteenth O site, O(13) is bonded to one Ba(1), one Ba(3), two equivalent Ba(6), one Nb(4), and one Ni(2) atom to form distorted OBa4NbNi octahedra that share  a cornercorner with one O(6)Ba4NbNi octahedra, corners with two equivalent O(1)Ba4Nb2 octahedra, corners with two equivalent O(12)Ba4NbNi octahedra, corners with two equivalent O(13)Ba4NbNi octahedra, corners with three equivalent O(3)Ba4Nb2 octahedra, corners with three equivalent O(4)Ba4Nb2 octahedra, corners with three equivalent O(9)Ba4NbNi octahedra,  an edgeedge with one O(1)Ba4Nb2 octahedra,  an edgeedge with one O(3)Ba4Nb2 octahedra,  an edgeedge with one O(13)Ba4NbNi octahedra,  a faceface with one O(3)Ba4Nb2 octahedra,  a faceface with one O(4)Ba4Nb2 octahedra, faces with two equivalent O(13)Ba4NbNi octahedra, and faces with two equivalent O(9)Ba4NbNi octahedra. The corner-sharing octahedral tilt angles range from 1-62°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba3Nb2NiO9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.845
_cell_length_b   5.845
_cell_length_c   7.180
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   59.998
_symmetry_Int_Tables_number   1
_cell_volume   212.406
_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
  Ba  Ba0  1  0.000  1.000  0.000  1.0
  Ba  Ba1  1  0.667  0.667  0.665  1.0
  Ba  Ba2  1  0.333  0.333  0.335  1.0
  Nb  Nb3  1  0.667  0.667  0.179  1.0
  Nb  Nb4  1  0.333  0.333  0.821  1.0
  Ni  Ni5  1  1.000  0.000  0.500  1.0
  O  O6  1  0.500  1.000  1.000  1.0
  O  O7  1  0.500  0.500  1.000  1.0
  O  O8  1  0.000  0.500  0.000  1.0
  O  O9  1  0.342  0.829  0.326  1.0
  O  O10  1  0.658  0.171  0.674  1.0
  O  O11  1  0.829  0.342  0.326  1.0
  O  O12  1  0.171  0.658  0.674  1.0
  O  O13  1  0.829  0.829  0.326  1.0
  O  O14  1  0.171  0.171  0.674  1.0
[/CIF]
.