The material structure described by Ni3(AsO4)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(3), one O(5), one O(7), one O(8), and two equivalent O(1) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, corners with three equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-60°. In the second Ni site, Ni(2) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form NiO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and  an edgeedge with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-60°. In the third Ni site, Ni(3) is bonded to one O(2), one O(6), one O(7), one O(8), and two equivalent O(4) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  an edgeedge with one Ni(3)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and  an edgeedge with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-55°. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, corners with three equivalent Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, and  an edgeedge with one Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-60°. In the second As site, As(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra, corners with three equivalent Ni(2)O6 octahedra, and corners with three equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-61°. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ni(2), two equivalent Ni(3), and one As(2) atom. In the second O site, O(5) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(2), and one As(1) atom. In the third O site, O(6) is bonded in a distorted trigonal planar geometry to one Ni(2), one Ni(3), and one As(1) atom. In the fourth O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Ni(2), one Ni(3), and one As(1) atom. In the fifth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(3), and one As(1) atom. In the sixth O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ni(1) and one As(2) atom. In the seventh O site, O(2) is bonded in a distorted trigonal planar geometry to one Ni(2), one Ni(3), and one As(2) atom. In the eighth O site, O(3) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(2), and one As(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ni3(AsO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.553
_cell_length_b   5.764
_cell_length_c   10.172
_cell_angle_alpha   87.114
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   559.354
_cell_formula_units_Z   4
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  0.865  0.615  0.035  1.0
  Ni  Ni1  1  0.365  0.385  0.465  1.0
  Ni  Ni2  1  0.135  0.385  0.965  1.0
  Ni  Ni3  1  0.635  0.615  0.535  1.0
  Ni  Ni4  1  0.863  0.858  0.285  1.0
  Ni  Ni5  1  0.363  0.142  0.215  1.0
  Ni  Ni6  1  0.137  0.142  0.715  1.0
  Ni  Ni7  1  0.637  0.858  0.785  1.0
  Ni  Ni8  1  0.623  0.136  0.058  1.0
  Ni  Ni9  1  0.123  0.864  0.442  1.0
  Ni  Ni10  1  0.877  0.136  0.558  1.0
  Ni  Ni11  1  0.377  0.864  0.942  1.0
  As  As12  1  0.845  0.132  0.882  1.0
  As  As13  1  0.345  0.868  0.618  1.0
  As  As14  1  0.155  0.868  0.118  1.0
  As  As15  1  0.655  0.132  0.382  1.0
  As  As16  1  0.944  0.624  0.705  1.0
  As  As17  1  0.444  0.376  0.795  1.0
  As  As18  1  0.056  0.376  0.295  1.0
  As  As19  1  0.556  0.624  0.205  1.0
  O  O20  1  0.007  0.384  0.134  1.0
  O  O21  1  0.507  0.616  0.366  1.0
  O  O22  1  0.993  0.616  0.866  1.0
  O  O23  1  0.493  0.384  0.634  1.0
  O  O24  1  0.496  0.383  0.132  1.0
  O  O25  1  0.996  0.617  0.368  1.0
  O  O26  1  0.504  0.617  0.868  1.0
  O  O27  1  0.004  0.383  0.632  1.0
  O  O28  1  0.735  0.631  0.196  1.0
  O  O29  1  0.235  0.369  0.304  1.0
  O  O30  1  0.265  0.369  0.804  1.0
  O  O31  1  0.765  0.631  0.696  1.0
  O  O32  1  0.988  0.127  0.377  1.0
  O  O33  1  0.488  0.873  0.123  1.0
  O  O34  1  0.012  0.873  0.623  1.0
  O  O35  1  0.512  0.127  0.877  1.0
  O  O36  1  0.522  0.870  0.618  1.0
  O  O37  1  0.022  0.130  0.882  1.0
  O  O38  1  0.478  0.130  0.382  1.0
  O  O39  1  0.978  0.870  0.118  1.0
  O  O40  1  0.775  0.113  0.729  1.0
  O  O41  1  0.275  0.887  0.771  1.0
  O  O42  1  0.225  0.887  0.271  1.0
  O  O43  1  0.725  0.113  0.229  1.0
  O  O44  1  0.754  0.894  0.954  1.0
  O  O45  1  0.254  0.106  0.546  1.0
  O  O46  1  0.733  0.344  0.467  1.0
  O  O47  1  0.746  0.894  0.454  1.0
  O  O48  1  0.767  0.344  0.967  1.0
  O  O49  1  0.267  0.656  0.533  1.0
  O  O50  1  0.233  0.656  0.033  1.0
  O  O51  1  0.246  0.106  0.046  1.0
[/CIF]
.
The material structure described by Ni3(AsO4)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(3), one O(5), one O(7), one O(8), and two equivalent O(1) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, corners with three equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-60°. In the second Ni site, Ni(2) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form NiO6 octahedra that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and  an edgeedge with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 55-60°. In the third Ni site, Ni(3) is bonded to one O(2), one O(6), one O(7), one O(8), and two equivalent O(4) atoms to form NiO6 octahedra that share  a cornercorner with one Ni(2)O6 octahedra, corners with two equivalent Ni(1)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  an edgeedge with one Ni(3)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and  an edgeedge with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-55°. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Ni(2)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, corners with three equivalent Ni(1)O6 octahedra,  an edgeedge with one Ni(2)O6 octahedra, and  an edgeedge with one Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-60°. In the second As site, As(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra, corners with three equivalent Ni(2)O6 octahedra, and corners with three equivalent Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-61°. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ni(2), two equivalent Ni(3), and one As(2) atom. In the second O site, O(5) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(2), and one As(1) atom. In the third O site, O(6) is bonded in a distorted trigonal planar geometry to one Ni(2), one Ni(3), and one As(1) atom. In the fourth O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Ni(2), one Ni(3), and one As(1) atom. In the fifth O site, O(8) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(3), and one As(1) atom. In the sixth O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ni(1) and one As(2) atom. In the seventh O site, O(2) is bonded in a distorted trigonal planar geometry to one Ni(2), one Ni(3), and one As(2) atom. In the eighth O site, O(3) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(2), and one As(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ni3(AsO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.553
_cell_length_b   5.764
_cell_length_c   10.172
_cell_angle_alpha   87.114
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   559.354
_cell_formula_units_Z   4
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  0.865  0.615  0.035  1.0
  Ni  Ni1  1  0.365  0.385  0.465  1.0
  Ni  Ni2  1  0.135  0.385  0.965  1.0
  Ni  Ni3  1  0.635  0.615  0.535  1.0
  Ni  Ni4  1  0.863  0.858  0.285  1.0
  Ni  Ni5  1  0.363  0.142  0.215  1.0
  Ni  Ni6  1  0.137  0.142  0.715  1.0
  Ni  Ni7  1  0.637  0.858  0.785  1.0
  Ni  Ni8  1  0.623  0.136  0.058  1.0
  Ni  Ni9  1  0.123  0.864  0.442  1.0
  Ni  Ni10  1  0.877  0.136  0.558  1.0
  Ni  Ni11  1  0.377  0.864  0.942  1.0
  As  As12  1  0.845  0.132  0.882  1.0
  As  As13  1  0.345  0.868  0.618  1.0
  As  As14  1  0.155  0.868  0.118  1.0
  As  As15  1  0.655  0.132  0.382  1.0
  As  As16  1  0.944  0.624  0.705  1.0
  As  As17  1  0.444  0.376  0.795  1.0
  As  As18  1  0.056  0.376  0.295  1.0
  As  As19  1  0.556  0.624  0.205  1.0
  O  O20  1  0.007  0.384  0.134  1.0
  O  O21  1  0.507  0.616  0.366  1.0
  O  O22  1  0.993  0.616  0.866  1.0
  O  O23  1  0.493  0.384  0.634  1.0
  O  O24  1  0.496  0.383  0.132  1.0
  O  O25  1  0.996  0.617  0.368  1.0
  O  O26  1  0.504  0.617  0.868  1.0
  O  O27  1  0.004  0.383  0.632  1.0
  O  O28  1  0.735  0.631  0.196  1.0
  O  O29  1  0.235  0.369  0.304  1.0
  O  O30  1  0.265  0.369  0.804  1.0
  O  O31  1  0.765  0.631  0.696  1.0
  O  O32  1  0.988  0.127  0.377  1.0
  O  O33  1  0.488  0.873  0.123  1.0
  O  O34  1  0.012  0.873  0.623  1.0
  O  O35  1  0.512  0.127  0.877  1.0
  O  O36  1  0.522  0.870  0.618  1.0
  O  O37  1  0.022  0.130  0.882  1.0
  O  O38  1  0.478  0.130  0.382  1.0
  O  O39  1  0.978  0.870  0.118  1.0
  O  O40  1  0.775  0.113  0.729  1.0
  O  O41  1  0.275  0.887  0.771  1.0
  O  O42  1  0.225  0.887  0.271  1.0
  O  O43  1  0.725  0.113  0.229  1.0
  O  O44  1  0.754  0.894  0.954  1.0
  O  O45  1  0.254  0.106  0.546  1.0
  O  O46  1  0.733  0.344  0.467  1.0
  O  O47  1  0.746  0.894  0.454  1.0
  O  O48  1  0.767  0.344  0.967  1.0
  O  O49  1  0.267  0.656  0.533  1.0
  O  O50  1  0.233  0.656  0.033  1.0
  O  O51  1  0.246  0.106  0.046  1.0
[/CIF]
.