data_CaSiAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.28
_cell_length_b   7.28
_cell_length_c   7.28
_cell_angle_alpha   30.11
_cell_angle_beta   30.11
_cell_angle_gamma   30.11
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaSiAs2
_chemical_formula_sum   'Ca1 Si1 As2'
_cell_volume   85.85
_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  Ca2  1  0.0  0.0  0.41  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0
  As  As0  1  0.0  0.0  0.56  1.0
  As  As1  1  0.0  0.0  0.26  1.0

data_CaSiAs2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.55
_cell_length_b   3.78
_cell_length_c   7.28
_cell_angle_alpha   90.0
_cell_angle_beta   107.45
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   CaSiAs2
_chemical_formula_sum   'Ca2 Si2 As4'
_cell_volume   171.69
_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+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.59  1.0
  Si  Si1  2  0.0  0.0  0.0  1.0
  As  As2  2  0.0  0.0  0.44  1.0
  As  As3  2  0.0  0.0  0.74  1.0

Ca Si As As
CaSiAs2 is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two CaSiAs2 clusters. Ca(1) is bonded in a linear geometry to one As(1) and one As(2) atom. The Ca(1)-As(1) bond length is 1.11 Å. The Ca(1)-As(2) bond length is 1.11 Å. Si(1) is bonded in a single-bond geometry to one As(2) atom. The Si(1)-As(2) bond length is 1.88 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a single-bond geometry to one Ca(1) atom. In the second As site, As(2) is bonded in a distorted single-bond geometry to one Ca(1) and one Si(1) atom.