The crystal structure described by CaNiAsO5 is Esseneite-like structured and crystallizes in the orthorhombic P2_12_12_1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(5), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Ni(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(5) atoms to form NiO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra and edges with two equivalent Ni(1)O6 octahedra. As(1) 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 four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-62°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Ni(1), and one As(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca(1) and one As(1) atom. In the third O site, O(3) is bonded to two equivalent Ca(1), one Ni(1), and one As(1) atom to form a mixture of distorted corner and edge-sharing OCa2NiAs tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Ca(1), one Ni(1), and one As(1) atom to form a mixture of distorted corner and edge-sharing OCa2NiAs trigonal pyramids. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Ca(1) and two equivalent Ni(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaNiAsO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.868
_cell_length_b   7.529
_cell_length_c   8.854
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   391.219
_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
  Ca  Ca0  1  0.974  0.849  0.667  1.0
  Ca  Ca1  1  0.526  0.151  0.167  1.0
  Ca  Ca2  1  0.026  0.349  0.833  1.0
  Ca  Ca3  1  0.474  0.651  0.333  1.0
  Ni  Ni4  1  0.251  0.754  0.996  1.0
  Ni  Ni5  1  0.249  0.246  0.496  1.0
  Ni  Ni6  1  0.749  0.254  0.504  1.0
  Ni  Ni7  1  0.751  0.746  0.004  1.0
  As  As8  1  0.483  0.107  0.807  1.0
  As  As9  1  0.017  0.893  0.307  1.0
  As  As10  1  0.517  0.607  0.693  1.0
  As  As11  1  0.983  0.393  0.193  1.0
  O  O12  1  0.508  0.923  0.927  1.0
  O  O13  1  0.992  0.077  0.427  1.0
  O  O14  1  0.492  0.423  0.573  1.0
  O  O15  1  0.008  0.577  0.073  1.0
  O  O16  1  0.413  0.274  0.928  1.0
  O  O17  1  0.087  0.726  0.428  1.0
  O  O18  1  0.587  0.774  0.572  1.0
  O  O19  1  0.913  0.226  0.072  1.0
  O  O20  1  0.741  0.133  0.716  1.0
  O  O21  1  0.759  0.867  0.216  1.0
  O  O22  1  0.259  0.633  0.784  1.0
  O  O23  1  0.241  0.367  0.284  1.0
  O  O24  1  0.249  0.093  0.690  1.0
  O  O25  1  0.251  0.907  0.190  1.0
  O  O26  1  0.751  0.593  0.810  1.0
  O  O27  1  0.749  0.407  0.310  1.0
  O  O28  1  0.996  0.873  0.926  1.0
  O  O29  1  0.504  0.127  0.426  1.0
  O  O30  1  0.004  0.373  0.574  1.0
  O  O31  1  0.496  0.627  0.074  1.0
[/CIF]
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The crystal structure described by CaNiAsO5 is Esseneite-like structured and crystallizes in the orthorhombic P2_12_12_1 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(1), one O(5), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Ni(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(5) atoms to form NiO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra and edges with two equivalent Ni(1)O6 octahedra. As(1) 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 four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 40-62°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Ni(1), and one As(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ca(1) and one As(1) atom. In the third O site, O(3) is bonded to two equivalent Ca(1), one Ni(1), and one As(1) atom to form a mixture of distorted corner and edge-sharing OCa2NiAs tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Ca(1), one Ni(1), and one As(1) atom to form a mixture of distorted corner and edge-sharing OCa2NiAs trigonal pyramids. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Ca(1) and two equivalent Ni(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaNiAsO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.868
_cell_length_b   7.529
_cell_length_c   8.854
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   391.219
_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
  Ca  Ca0  1  0.974  0.849  0.667  1.0
  Ca  Ca1  1  0.526  0.151  0.167  1.0
  Ca  Ca2  1  0.026  0.349  0.833  1.0
  Ca  Ca3  1  0.474  0.651  0.333  1.0
  Ni  Ni4  1  0.251  0.754  0.996  1.0
  Ni  Ni5  1  0.249  0.246  0.496  1.0
  Ni  Ni6  1  0.749  0.254  0.504  1.0
  Ni  Ni7  1  0.751  0.746  0.004  1.0
  As  As8  1  0.483  0.107  0.807  1.0
  As  As9  1  0.017  0.893  0.307  1.0
  As  As10  1  0.517  0.607  0.693  1.0
  As  As11  1  0.983  0.393  0.193  1.0
  O  O12  1  0.508  0.923  0.927  1.0
  O  O13  1  0.992  0.077  0.427  1.0
  O  O14  1  0.492  0.423  0.573  1.0
  O  O15  1  0.008  0.577  0.073  1.0
  O  O16  1  0.413  0.274  0.928  1.0
  O  O17  1  0.087  0.726  0.428  1.0
  O  O18  1  0.587  0.774  0.572  1.0
  O  O19  1  0.913  0.226  0.072  1.0
  O  O20  1  0.741  0.133  0.716  1.0
  O  O21  1  0.759  0.867  0.216  1.0
  O  O22  1  0.259  0.633  0.784  1.0
  O  O23  1  0.241  0.367  0.284  1.0
  O  O24  1  0.249  0.093  0.690  1.0
  O  O25  1  0.251  0.907  0.190  1.0
  O  O26  1  0.751  0.593  0.810  1.0
  O  O27  1  0.749  0.407  0.310  1.0
  O  O28  1  0.996  0.873  0.926  1.0
  O  O29  1  0.504  0.127  0.426  1.0
  O  O30  1  0.004  0.373  0.574  1.0
  O  O31  1  0.496  0.627  0.074  1.0
[/CIF]
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