data_Cr2SiAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.1
_cell_length_b   3.1
_cell_length_c   5.3
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cr2SiAs
_chemical_formula_sum   'Cr2 Si1 As1'
_cell_volume   50.8
_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
  Cr  Cr1  1  0.0  0.0  0.18  1.0
  Cr  Cr2  1  0.55  0.55  0.49  1.0
  Si  Si3  1  0.0  0.0  0.5  1.0
  As  As0  1  0.55  0.55  0.08  1.0

data_Cr2SiAs
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.38
_cell_length_b   4.38
_cell_length_c   5.3
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Cr2SiAs
_chemical_formula_sum   'Cr4 Si2 As2'
_cell_volume   101.61
_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
  Cr  Cr0  2  0.0  0.0  0.18  1.0
  Cr  Cr1  2  0.05  0.5  0.49  1.0
  Si  Si2  2  0.0  0.0  0.5  1.0
  As  As3  2  0.05  0.5  0.08  1.0

Cr Cr Si As
Cr2SiAs crystallizes in the monoclinic Cm space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 5-coordinate geometry to one Si(1) and four equivalent As(1) atoms. The Cr(1)-Si(1) bond length is 1.68 Å. There are a spread of Cr(1)-As(1) bond distances ranging from 2.05-2.46 Å. In the second Cr site, Cr(2) is bonded in a 6-coordinate geometry to four equivalent Si(1) and two equivalent As(1) atoms. There are a spread of Cr(2)-Si(1) bond distances ranging from 1.98-2.40 Å. There is one shorter (2.18 Å) and one longer (3.12 Å) Cr(2)-As(1) bond length. Si(1) is bonded to one Cr(1) and four equivalent Cr(2) atoms to form a mixture of distorted corner and edge-sharing SiCr5 square pyramids. As(1) is bonded in a 6-coordinate geometry to two equivalent Cr(2) and four equivalent Cr(1) atoms.