data_Cr2AsSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.04
_cell_length_b   3.04
_cell_length_c   7.3
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cr2AsSe
_chemical_formula_sum   'Cr2 As1 Se1'
_cell_volume   67.37
_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  0.52  0.52  0.29  1.0
  Cr  Cr2  1  0.0  0.0  0.57  1.0
  As  As0  1  0.0  0.0  0.18  1.0
  Se  Se3  1  0.52  0.52  0.9  1.0

data_Cr2AsSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.3
_cell_length_b   4.3
_cell_length_c   7.3
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Cr2AsSe
_chemical_formula_sum   'Cr4 As2 Se2'
_cell_volume   134.74
_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  0.57  1.0
  Cr  Cr1  2  0.02  0.5  0.29  1.0
  As  As2  2  0.0  0.0  0.18  1.0
  Se  Se3  2  0.02  0.5  0.9  1.0

Cr Cr As Se
Cr2AsSe crystallizes in the monoclinic Cm space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 4-coordinate geometry to four equivalent Cr(2), four equivalent As(1), and one Se(1) atom. There are a spread of Cr(1)-Cr(2) bond distances ranging from 2.91-3.03 Å. There are a spread of Cr(1)-As(1) bond distances ranging from 2.22-2.38 Å. The Cr(1)-Se(1) bond length is 2.87 Å. In the second Cr site, Cr(2) is bonded in a 13-coordinate geometry to four equivalent Cr(1), four equivalent Cr(2), one As(1), and four equivalent Se(1) atoms. All Cr(2)-Cr(2) bond lengths are 3.04 Å. The Cr(2)-As(1) bond length is 2.88 Å. There are a spread of Cr(2)-Se(1) bond distances ranging from 3.14-3.26 Å. As(1) is bonded in a 4-coordinate geometry to one Cr(2), four equivalent Cr(1), and four equivalent Se(1) atoms. There are a spread of As(1)-Se(1) bond distances ranging from 2.91-3.03 Å. Se(1) is bonded in a 13-coordinate geometry to one Cr(1), four equivalent Cr(2), four equivalent As(1), and four equivalent Se(1) atoms. All Se(1)-Se(1) bond lengths are 3.04 Å.