data_CaNiAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.71
_cell_length_b   5.68
_cell_length_c   3.32
_cell_angle_alpha   73.56
_cell_angle_beta   72.54
_cell_angle_gamma   33.91
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaNiAs
_chemical_formula_sum   'Ca1 Ni1 As1'
_cell_volume   57.31
_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
  Ca  Ca1  1  0.31  0.39  0.92  1.0
  Ni  Ni2  1  0.31  0.39  0.9  1.0
  As  As0  1  0.31  0.39  0.94  1.0

data_CaNiAs
_symmetry_space_group_name_H-M   Imm2
_cell_length_a   3.32
_cell_length_b   10.38
_cell_length_c   3.32
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   44
_chemical_formula_structural   CaNiAs
_chemical_formula_sum   'Ca2 Ni2 As2'
_cell_volume   114.68
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, z'
  3  '-x, y, z'
  4  'x, -y, z'
  5  'x+1/2, y+1/2, z+1/2'
  6  '-x+1/2, -y+1/2, z+1/2'
  7  '-x+1/2, y+1/2, z+1/2'
  8  'x+1/2, -y+1/2, z+1/2'
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  2  0.0  0.0  0.76  1.0
  Ni  Ni1  2  0.0  0.0  0.79  1.0
  As  As2  2  0.0  0.0  0.75  1.0

Ca Ni As
Ca Ni As 0 2 o o o 0 1 o o o 
CaNiAs is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two CaNiAs clusters. Ca(1) is bonded in a linear geometry to one Ni(1) and one As(1) atom. The Ca(1)-Ni(1) bond length is 0.07 Å. The Ca(1)-As(1) bond length is 0.05 Å. Ni(1) is bonded in a single-bond geometry to one Ca(1) atom. As(1) is bonded in a single-bond geometry to one Ca(1) atom.