The compound described by Ni2As2O7 crystallizes in the monoclinic C2/m space group. Ni(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form distorted NiO6 pentagonal pyramids that share corners with six equivalent As(1)O4 tetrahedra and edges with three equivalent Ni(1)O6 pentagonal pyramids. As(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted AsO4 tetrahedra that share corners with six equivalent Ni(1)O6 pentagonal pyramids and  a cornercorner with one As(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent As(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ni(1) and one As(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ni(1) and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ni2As2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.831
_cell_length_b   5.406
_cell_length_c   5.406
_cell_angle_alpha   106.865
_cell_angle_beta   96.840
_cell_angle_gamma   96.839
_symmetry_Int_Tables_number   1
_cell_volume   132.365
_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
  As  As0  1  0.897  0.242  0.242  1.0
  As  As1  1  0.103  0.758  0.758  1.0
  Ni  Ni2  1  0.500  0.688  0.312  1.0
  Ni  Ni3  1  0.500  0.312  0.688  1.0
  O  O4  1  0.000  0.000  0.000  1.0
  O  O5  1  0.773  0.592  0.592  1.0
  O  O6  1  0.227  0.408  0.408  1.0
  O  O7  1  0.710  0.406  0.070  1.0
  O  O8  1  0.290  0.930  0.594  1.0
  O  O9  1  0.290  0.594  0.930  1.0
  O  O10  1  0.710  0.070  0.406  1.0
[/CIF]
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The compound described by Ni2As2O7 crystallizes in the monoclinic C2/m space group. Ni(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form distorted NiO6 pentagonal pyramids that share corners with six equivalent As(1)O4 tetrahedra and edges with three equivalent Ni(1)O6 pentagonal pyramids. As(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted AsO4 tetrahedra that share corners with six equivalent Ni(1)O6 pentagonal pyramids and  a cornercorner with one As(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent As(1) atoms. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Ni(1) and one As(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ni(1) and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ni2As2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.831
_cell_length_b   5.406
_cell_length_c   5.406
_cell_angle_alpha   106.865
_cell_angle_beta   96.840
_cell_angle_gamma   96.839
_symmetry_Int_Tables_number   1
_cell_volume   132.365
_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
  As  As0  1  0.897  0.242  0.242  1.0
  As  As1  1  0.103  0.758  0.758  1.0
  Ni  Ni2  1  0.500  0.688  0.312  1.0
  Ni  Ni3  1  0.500  0.312  0.688  1.0
  O  O4  1  0.000  0.000  0.000  1.0
  O  O5  1  0.773  0.592  0.592  1.0
  O  O6  1  0.227  0.408  0.408  1.0
  O  O7  1  0.710  0.406  0.070  1.0
  O  O8  1  0.290  0.930  0.594  1.0
  O  O9  1  0.290  0.594  0.930  1.0
  O  O10  1  0.710  0.070  0.406  1.0
[/CIF]
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