data_SrCr2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.22
_cell_length_b   3.22
_cell_length_c   7.21
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrCr2Se
_chemical_formula_sum   'Sr1 Cr2 Se1'
_cell_volume   74.63
_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
  Sr  Sr3  1  0.61  0.61  0.4  1.0
  Cr  Cr0  1  0.0  0.0  0.67  1.0
  Cr  Cr1  1  0.61  0.61  0.64  1.0
  Se  Se2  1  0.0  0.0  0.11  1.0

data_SrCr2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.55
_cell_length_b   4.55
_cell_length_c   7.21
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   SrCr2Se
_chemical_formula_sum   'Sr2 Cr4 Se2'
_cell_volume   149.26
_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
  Sr  Sr0  2  0.11  0.5  0.4  1.0
  Cr  Cr1  2  0.0  0.0  0.67  1.0
  Cr  Cr2  2  0.11  0.5  0.64  1.0
  Se  Se3  2  0.0  0.0  0.11  1.0

Sr Cr Cr Se
SrCr2Se crystallizes in the monoclinic Cm space group. Sr(1) is bonded in a 1-coordinate geometry to one Cr(2) and four equivalent Se(1) atoms. The Sr(1)-Cr(2) bond length is 1.73 Å. There are a spread of Sr(1)-Se(1) bond distances ranging from 2.73-3.46 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 4-coordinate geometry to three equivalent Cr(2) and one Se(1) atom. There is one shorter (1.79 Å) and two longer (2.34 Å) Cr(1)-Cr(2) bond lengths. The Cr(1)-Se(1) bond length is 3.18 Å. In the second Cr site, Cr(2) is bonded in a distorted single-bond geometry to one Sr(1) and three equivalent Cr(1) atoms. Se(1) is bonded in a 5-coordinate geometry to four equivalent Sr(1) and one Cr(1) atom.