The structure described by BaNi2(AsO4)2 crystallizes in the trigonal R-3 space group. Ba(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ni(1)O6 octahedra, edges with six equivalent Ba(1)O12 cuboctahedra, edges with six equivalent As(1)O4 tetrahedra, and faces with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. Ni(1) is bonded to six equivalent O(2) atoms to form NiO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with six equivalent As(1)O4 tetrahedra, edges with three equivalent Ni(1)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. As(1) is bonded to one O(1) and three equivalent O(2) atoms to form AsO4 tetrahedra that share corners with six equivalent Ni(1)O6 octahedra and edges with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 54-57°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one As(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), two equivalent Ni(1), and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_BaNi2(AsO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.025
_cell_length_b   5.025
_cell_length_c   8.557
_cell_angle_alpha   72.925
_cell_angle_beta   72.925
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   176.020
_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  0.428  0.428  0.717  1.0
  As  As1  1  0.572  0.572  0.283  1.0
  Ba  Ba2  1  0.000  0.000  0.000  1.0
  Ni  Ni3  1  0.169  0.169  0.494  1.0
  Ni  Ni4  1  0.831  0.831  0.506  1.0
  O  O5  1  0.642  0.642  0.073  1.0
  O  O6  1  0.358  0.358  0.927  1.0
  O  O7  1  0.123  0.785  0.651  1.0
  O  O8  1  0.785  0.440  0.651  1.0
  O  O9  1  0.440  0.123  0.651  1.0
  O  O10  1  0.877  0.215  0.349  1.0
  O  O11  1  0.215  0.560  0.349  1.0
  O  O12  1  0.560  0.877  0.349  1.0
[/CIF]
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The structure described by BaNi2(AsO4)2 crystallizes in the trigonal R-3 space group. Ba(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ni(1)O6 octahedra, edges with six equivalent Ba(1)O12 cuboctahedra, edges with six equivalent As(1)O4 tetrahedra, and faces with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. Ni(1) is bonded to six equivalent O(2) atoms to form NiO6 octahedra that share corners with three equivalent Ba(1)O12 cuboctahedra, corners with six equivalent As(1)O4 tetrahedra, edges with three equivalent Ni(1)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. As(1) is bonded to one O(1) and three equivalent O(2) atoms to form AsO4 tetrahedra that share corners with six equivalent Ni(1)O6 octahedra and edges with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 54-57°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one As(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ba(1), two equivalent Ni(1), and one As(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_BaNi2(AsO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.025
_cell_length_b   5.025
_cell_length_c   8.557
_cell_angle_alpha   72.925
_cell_angle_beta   72.925
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   176.020
_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  0.428  0.428  0.717  1.0
  As  As1  1  0.572  0.572  0.283  1.0
  Ba  Ba2  1  0.000  0.000  0.000  1.0
  Ni  Ni3  1  0.169  0.169  0.494  1.0
  Ni  Ni4  1  0.831  0.831  0.506  1.0
  O  O5  1  0.642  0.642  0.073  1.0
  O  O6  1  0.358  0.358  0.927  1.0
  O  O7  1  0.123  0.785  0.651  1.0
  O  O8  1  0.785  0.440  0.651  1.0
  O  O9  1  0.440  0.123  0.651  1.0
  O  O10  1  0.877  0.215  0.349  1.0
  O  O11  1  0.215  0.560  0.349  1.0
  O  O12  1  0.560  0.877  0.349  1.0
[/CIF]
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