The crystal structure described by Ni5(AsO6)2 crystallizes in the monoclinic C2/m space group. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. In the third Ni site, Ni(3) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NiO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. As(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form AsO4 tetrahedra that share  a cornercorner with one Ni(3)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra, and corners with four equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-56°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(2), and one As(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ni(3), two equivalent Ni(1), and one As(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Ni(2) and one As(1) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Ni(1), one Ni(2), and one Ni(3) atom. is represented by the CIF file [CIF]
data_Ni5(AsO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.462
_cell_length_b   6.462
_cell_length_c   5.119
_cell_angle_alpha   85.062
_cell_angle_beta   85.062
_cell_angle_gamma   86.561
_symmetry_Int_Tables_number   1
_cell_volume   211.865
_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
  Ni  Ni0  1  0.177  0.823  0.000  1.0
  Ni  Ni1  1  0.823  0.177  0.000  1.0
  Ni  Ni2  1  0.338  0.662  0.500  1.0
  Ni  Ni3  1  0.662  0.338  0.500  1.0
  Ni  Ni4  1  0.000  0.000  0.500  1.0
  As  As5  1  0.684  0.684  0.947  1.0
  As  As6  1  0.316  0.316  0.053  1.0
  O  O7  1  0.211  0.529  0.876  1.0
  O  O8  1  0.529  0.211  0.876  1.0
  O  O9  1  0.789  0.471  0.124  1.0
  O  O10  1  0.471  0.789  0.124  1.0
  O  O11  1  0.872  0.872  0.890  1.0
  O  O12  1  0.128  0.128  0.110  1.0
  O  O13  1  0.623  0.623  0.637  1.0
  O  O14  1  0.377  0.377  0.363  1.0
  O  O15  1  0.077  0.742  0.359  1.0
  O  O16  1  0.742  0.077  0.359  1.0
  O  O17  1  0.923  0.258  0.641  1.0
  O  O18  1  0.258  0.923  0.641  1.0
[/CIF]
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The crystal structure described by Ni5(AsO6)2 crystallizes in the monoclinic C2/m space group. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with two equivalent Ni(3)O6 octahedra. In the second Ni site, Ni(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra,  an edgeedge with one Ni(2)O6 octahedra,  an edgeedge with one Ni(3)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. In the third Ni site, Ni(3) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NiO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. As(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form AsO4 tetrahedra that share  a cornercorner with one Ni(3)O6 octahedra, corners with four equivalent Ni(1)O6 octahedra, and corners with four equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-56°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(2), and one As(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ni(3), two equivalent Ni(1), and one As(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Ni(2) and one As(1) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Ni(1), one Ni(2), and one Ni(3) atom. is represented by the CIF file [CIF]
data_Ni5(AsO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.462
_cell_length_b   6.462
_cell_length_c   5.119
_cell_angle_alpha   85.062
_cell_angle_beta   85.062
_cell_angle_gamma   86.561
_symmetry_Int_Tables_number   1
_cell_volume   211.865
_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
  Ni  Ni0  1  0.177  0.823  0.000  1.0
  Ni  Ni1  1  0.823  0.177  0.000  1.0
  Ni  Ni2  1  0.338  0.662  0.500  1.0
  Ni  Ni3  1  0.662  0.338  0.500  1.0
  Ni  Ni4  1  0.000  0.000  0.500  1.0
  As  As5  1  0.684  0.684  0.947  1.0
  As  As6  1  0.316  0.316  0.053  1.0
  O  O7  1  0.211  0.529  0.876  1.0
  O  O8  1  0.529  0.211  0.876  1.0
  O  O9  1  0.789  0.471  0.124  1.0
  O  O10  1  0.471  0.789  0.124  1.0
  O  O11  1  0.872  0.872  0.890  1.0
  O  O12  1  0.128  0.128  0.110  1.0
  O  O13  1  0.623  0.623  0.637  1.0
  O  O14  1  0.377  0.377  0.363  1.0
  O  O15  1  0.077  0.742  0.359  1.0
  O  O16  1  0.742  0.077  0.359  1.0
  O  O17  1  0.923  0.258  0.641  1.0
  O  O18  1  0.258  0.923  0.641  1.0
[/CIF]
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