The material structure described by NiO2 crystallizes in the monoclinic Cm space group. There are twelve inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one Ni(12)O4 tetrahedra, corners with two equivalent Ni(5)O4 tetrahedra,  an edgeedge with one Ni(11)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. In the second Ni site, Ni(2) is bonded to one O(4), one O(9), two equivalent O(5), and two equivalent O(6) atoms to form NiO6 octahedra that share corners with three equivalent Ni(5)O4 tetrahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. In the third Ni site, Ni(3) is bonded to one O(15), one O(7), and two equivalent O(10) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the fourth Ni site, Ni(4) is bonded to one O(11), one O(12), one O(14), one O(5), one O(7), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(5)O4 tetrahedra, corners with two equivalent Ni(8)O4 tetrahedra,  an edgeedge with one Ni(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. In the fifth Ni site, Ni(5) is bonded to one O(14), one O(4), and two equivalent O(6) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-61°. In the sixth Ni site, Ni(6) is bonded to one O(13), one O(21), and two equivalent O(17) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the seventh Ni site, Ni(7) is bonded to one O(10), one O(13), one O(15), one O(16), one O(18), and one O(20) atom to form NiO6 octahedra that share  a cornercorner with one Ni(6)O4 tetrahedra,  a cornercorner with one Ni(8)O4 tetrahedra, corners with two equivalent Ni(10)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra, and edges with two equivalent Ni(7)O6 octahedra. In the eighth Ni site, Ni(8) is bonded to one O(11), one O(20), and two equivalent O(12) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-57°. In the ninth Ni site, Ni(9) is bonded to one O(17), one O(19), one O(21), one O(22), one O(23), and one O(24) atom to form NiO6 octahedra that share  a cornercorner with one Ni(10)O4 tetrahedra, corners with two equivalent Ni(12)O4 tetrahedra, corners with two equivalent Ni(6)O4 tetrahedra,  an edgeedge with one Ni(11)O6 octahedra, and edges with two equivalent Ni(9)O6 octahedra. In the tenth Ni site, Ni(10) is bonded to one O(16), one O(24), and two equivalent O(18) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-57°. In the eleventh Ni site, Ni(11) is bonded to one O(22), one O(3), two equivalent O(1), and two equivalent O(23) atoms to form NiO6 octahedra that share corners with three equivalent Ni(12)O4 tetrahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(9)O6 octahedra. In the twelfth Ni site, Ni(12) is bonded to one O(22), one O(8), and two equivalent O(23) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-59°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Ni(1) and one Ni(11) atom. In the second O site, O(2) is bonded in a water-like geometry to two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ni(11) and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal pyramidal geometry to one Ni(2), one Ni(5), and two equivalent Ni(1) atoms. In the fifth O site, O(5) is bonded in a water-like geometry to one Ni(2) and one Ni(4) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Ni(1), one Ni(2), and one Ni(5) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Ni(3) and two equivalent Ni(4) atoms. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Ni(12) and two equivalent Ni(1) atoms. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Ni(2) and two equivalent Ni(4) atoms. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Ni(3) and one Ni(7) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Ni(8) and two equivalent Ni(4) atoms. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Ni(4) and one Ni(8) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Ni(6) and two equivalent Ni(7) atoms. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Ni(5) and two equivalent Ni(4) atoms. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Ni(3) and two equivalent Ni(7) atoms. In the sixteenth O site, O(16) is bonded in a trigonal planar geometry to one Ni(10) and two equivalent Ni(7) atoms. In the seventeenth O site, O(17) is bonded in a bent 120 degrees geometry to one Ni(6) and one Ni(9) atom. In the eighteenth O site, O(18) is bonded in a bent 120 degrees geometry to one Ni(10) and one Ni(7) atom. In the nineteenth O site, O(19) is bonded in a water-like geometry to two equivalent Ni(9) atoms. In the twentieth O site, O(20) is bonded in a trigonal planar geometry to one Ni(8) and two equivalent Ni(7) atoms. In the twenty-first O site, O(21) is bonded in a trigonal planar geometry to one Ni(6) and two equivalent Ni(9) atoms. In the twenty-second O site, O(22) is bonded in a distorted trigonal pyramidal geometry to one Ni(11), one Ni(12), and two equivalent Ni(9) atoms. In the twenty-third O site, O(23) is bonded in a trigonal planar geometry to one Ni(11), one Ni(12), and one Ni(9) atom. In the twenty-fourth O site, O(24) is bonded in a trigonal planar geometry to one Ni(10) and two equivalent Ni(9) atoms. is represented by the CIF card [CIF]
data_NiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.749
_cell_length_b   5.749
_cell_length_c   18.820
_cell_angle_alpha   80.675
_cell_angle_beta   80.675
_cell_angle_gamma   59.933
_symmetry_Int_Tables_number   1
_cell_volume   528.863
_cell_formula_units_Z   16
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
  Ni  Ni0  1  0.379  0.873  0.875  1.0
  Ni  Ni1  1  0.253  0.253  0.747  1.0
  Ni  Ni2  1  0.873  0.379  0.875  1.0
  Ni  Ni3  1  0.348  0.348  0.466  1.0
  Ni  Ni4  1  0.125  0.623  0.622  1.0
  Ni  Ni5  1  0.903  0.903  0.779  1.0
  Ni  Ni6  1  0.099  0.099  0.217  1.0
  Ni  Ni7  1  0.623  0.125  0.622  1.0
  Ni  Ni8  1  0.876  0.376  0.376  1.0
  Ni  Ni9  1  0.650  0.650  0.537  1.0
  Ni  Ni10  1  0.376  0.876  0.376  1.0
  Ni  Ni11  1  0.122  0.626  0.129  1.0
  Ni  Ni12  1  0.626  0.122  0.129  1.0
  Ni  Ni13  1  0.405  0.405  0.283  1.0
  Ni  Ni14  1  0.501  0.501  1.000  1.0
  Ni  Ni15  1  0.153  0.153  0.030  1.0
  O  O16  1  0.677  0.238  0.936  1.0
  O  O17  1  0.570  0.570  0.824  1.0
  O  O18  1  0.238  0.677  0.936  1.0
  O  O19  1  0.671  0.671  0.934  1.0
  O  O20  1  0.078  0.078  0.816  1.0
  O  O21  1  0.430  0.983  0.685  1.0
  O  O22  1  0.528  0.056  0.810  1.0
  O  O23  1  0.323  0.323  0.567  1.0
  O  O24  1  0.983  0.430  0.685  1.0
  O  O25  1  0.174  0.174  0.928  1.0
  O  O26  1  0.419  0.419  0.681  1.0
  O  O27  1  0.056  0.528  0.810  1.0
  O  O28  1  0.195  0.704  0.433  1.0
  O  O29  1  0.817  0.817  0.569  1.0
  O  O30  1  0.291  0.805  0.565  1.0
  O  O31  1  0.077  0.077  0.317  1.0
  O  O32  1  0.704  0.195  0.433  1.0
  O  O33  1  0.924  0.924  0.677  1.0
  O  O34  1  0.186  0.186  0.430  1.0
  O  O35  1  0.805  0.291  0.565  1.0
  O  O36  1  0.566  0.566  0.321  1.0
  O  O37  1  0.943  0.460  0.187  1.0
  O  O38  1  0.049  0.555  0.318  1.0
  O  O39  1  0.826  0.826  0.074  1.0
  O  O40  1  0.460  0.943  0.187  1.0
  O  O41  1  0.674  0.674  0.435  1.0
  O  O42  1  0.935  0.935  0.183  1.0
  O  O43  1  0.555  0.049  0.318  1.0
  O  O44  1  0.327  0.327  0.066  1.0
  O  O45  1  0.778  0.307  0.062  1.0
  O  O46  1  0.427  0.427  0.183  1.0
  O  O47  1  0.307  0.778  0.062  1.0
[/CIF]
.
The material structure described by NiO2 crystallizes in the monoclinic Cm space group. There are twelve inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one Ni(12)O4 tetrahedra, corners with two equivalent Ni(5)O4 tetrahedra,  an edgeedge with one Ni(11)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. In the second Ni site, Ni(2) is bonded to one O(4), one O(9), two equivalent O(5), and two equivalent O(6) atoms to form NiO6 octahedra that share corners with three equivalent Ni(5)O4 tetrahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. In the third Ni site, Ni(3) is bonded to one O(15), one O(7), and two equivalent O(10) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the fourth Ni site, Ni(4) is bonded to one O(11), one O(12), one O(14), one O(5), one O(7), and one O(9) atom to form NiO6 octahedra that share  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(5)O4 tetrahedra, corners with two equivalent Ni(8)O4 tetrahedra,  an edgeedge with one Ni(2)O6 octahedra, and edges with two equivalent Ni(4)O6 octahedra. In the fifth Ni site, Ni(5) is bonded to one O(14), one O(4), and two equivalent O(6) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-61°. In the sixth Ni site, Ni(6) is bonded to one O(13), one O(21), and two equivalent O(17) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-56°. In the seventh Ni site, Ni(7) is bonded to one O(10), one O(13), one O(15), one O(16), one O(18), and one O(20) atom to form NiO6 octahedra that share  a cornercorner with one Ni(6)O4 tetrahedra,  a cornercorner with one Ni(8)O4 tetrahedra, corners with two equivalent Ni(10)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra, and edges with two equivalent Ni(7)O6 octahedra. In the eighth Ni site, Ni(8) is bonded to one O(11), one O(20), and two equivalent O(12) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-57°. In the ninth Ni site, Ni(9) is bonded to one O(17), one O(19), one O(21), one O(22), one O(23), and one O(24) atom to form NiO6 octahedra that share  a cornercorner with one Ni(10)O4 tetrahedra, corners with two equivalent Ni(12)O4 tetrahedra, corners with two equivalent Ni(6)O4 tetrahedra,  an edgeedge with one Ni(11)O6 octahedra, and edges with two equivalent Ni(9)O6 octahedra. In the tenth Ni site, Ni(10) is bonded to one O(16), one O(24), and two equivalent O(18) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-57°. In the eleventh Ni site, Ni(11) is bonded to one O(22), one O(3), two equivalent O(1), and two equivalent O(23) atoms to form NiO6 octahedra that share corners with three equivalent Ni(12)O4 tetrahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with two equivalent Ni(9)O6 octahedra. In the twelfth Ni site, Ni(12) is bonded to one O(22), one O(8), and two equivalent O(23) atoms to form corner-sharing NiO4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-59°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Ni(1) and one Ni(11) atom. In the second O site, O(2) is bonded in a water-like geometry to two equivalent Ni(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ni(11) and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal pyramidal geometry to one Ni(2), one Ni(5), and two equivalent Ni(1) atoms. In the fifth O site, O(5) is bonded in a water-like geometry to one Ni(2) and one Ni(4) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Ni(1), one Ni(2), and one Ni(5) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Ni(3) and two equivalent Ni(4) atoms. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Ni(12) and two equivalent Ni(1) atoms. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one Ni(2) and two equivalent Ni(4) atoms. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Ni(3) and one Ni(7) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Ni(8) and two equivalent Ni(4) atoms. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Ni(4) and one Ni(8) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Ni(6) and two equivalent Ni(7) atoms. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Ni(5) and two equivalent Ni(4) atoms. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Ni(3) and two equivalent Ni(7) atoms. In the sixteenth O site, O(16) is bonded in a trigonal planar geometry to one Ni(10) and two equivalent Ni(7) atoms. In the seventeenth O site, O(17) is bonded in a bent 120 degrees geometry to one Ni(6) and one Ni(9) atom. In the eighteenth O site, O(18) is bonded in a bent 120 degrees geometry to one Ni(10) and one Ni(7) atom. In the nineteenth O site, O(19) is bonded in a water-like geometry to two equivalent Ni(9) atoms. In the twentieth O site, O(20) is bonded in a trigonal planar geometry to one Ni(8) and two equivalent Ni(7) atoms. In the twenty-first O site, O(21) is bonded in a trigonal planar geometry to one Ni(6) and two equivalent Ni(9) atoms. In the twenty-second O site, O(22) is bonded in a distorted trigonal pyramidal geometry to one Ni(11), one Ni(12), and two equivalent Ni(9) atoms. In the twenty-third O site, O(23) is bonded in a trigonal planar geometry to one Ni(11), one Ni(12), and one Ni(9) atom. In the twenty-fourth O site, O(24) is bonded in a trigonal planar geometry to one Ni(10) and two equivalent Ni(9) atoms. is represented by the CIF card [CIF]
data_NiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.749
_cell_length_b   5.749
_cell_length_c   18.820
_cell_angle_alpha   80.675
_cell_angle_beta   80.675
_cell_angle_gamma   59.933
_symmetry_Int_Tables_number   1
_cell_volume   528.863
_cell_formula_units_Z   16
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
  Ni  Ni0  1  0.379  0.873  0.875  1.0
  Ni  Ni1  1  0.253  0.253  0.747  1.0
  Ni  Ni2  1  0.873  0.379  0.875  1.0
  Ni  Ni3  1  0.348  0.348  0.466  1.0
  Ni  Ni4  1  0.125  0.623  0.622  1.0
  Ni  Ni5  1  0.903  0.903  0.779  1.0
  Ni  Ni6  1  0.099  0.099  0.217  1.0
  Ni  Ni7  1  0.623  0.125  0.622  1.0
  Ni  Ni8  1  0.876  0.376  0.376  1.0
  Ni  Ni9  1  0.650  0.650  0.537  1.0
  Ni  Ni10  1  0.376  0.876  0.376  1.0
  Ni  Ni11  1  0.122  0.626  0.129  1.0
  Ni  Ni12  1  0.626  0.122  0.129  1.0
  Ni  Ni13  1  0.405  0.405  0.283  1.0
  Ni  Ni14  1  0.501  0.501  1.000  1.0
  Ni  Ni15  1  0.153  0.153  0.030  1.0
  O  O16  1  0.677  0.238  0.936  1.0
  O  O17  1  0.570  0.570  0.824  1.0
  O  O18  1  0.238  0.677  0.936  1.0
  O  O19  1  0.671  0.671  0.934  1.0
  O  O20  1  0.078  0.078  0.816  1.0
  O  O21  1  0.430  0.983  0.685  1.0
  O  O22  1  0.528  0.056  0.810  1.0
  O  O23  1  0.323  0.323  0.567  1.0
  O  O24  1  0.983  0.430  0.685  1.0
  O  O25  1  0.174  0.174  0.928  1.0
  O  O26  1  0.419  0.419  0.681  1.0
  O  O27  1  0.056  0.528  0.810  1.0
  O  O28  1  0.195  0.704  0.433  1.0
  O  O29  1  0.817  0.817  0.569  1.0
  O  O30  1  0.291  0.805  0.565  1.0
  O  O31  1  0.077  0.077  0.317  1.0
  O  O32  1  0.704  0.195  0.433  1.0
  O  O33  1  0.924  0.924  0.677  1.0
  O  O34  1  0.186  0.186  0.430  1.0
  O  O35  1  0.805  0.291  0.565  1.0
  O  O36  1  0.566  0.566  0.321  1.0
  O  O37  1  0.943  0.460  0.187  1.0
  O  O38  1  0.049  0.555  0.318  1.0
  O  O39  1  0.826  0.826  0.074  1.0
  O  O40  1  0.460  0.943  0.187  1.0
  O  O41  1  0.674  0.674  0.435  1.0
  O  O42  1  0.935  0.935  0.183  1.0
  O  O43  1  0.555  0.049  0.318  1.0
  O  O44  1  0.327  0.327  0.066  1.0
  O  O45  1  0.778  0.307  0.062  1.0
  O  O46  1  0.427  0.427  0.183  1.0
  O  O47  1  0.307  0.778  0.062  1.0
[/CIF]
.