data_SrGa2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.56
_cell_length_b   6.56
_cell_length_c   6.56
_cell_angle_alpha   142.33
_cell_angle_beta   142.33
_cell_angle_gamma   54.33
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrGa2Se
_chemical_formula_sum   'Sr1 Ga2 Se1'
_cell_volume   104.75
_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  0.0  0.0  0.84  1.0
  Ga  Ga0  1  0.0  0.12  0.92  1.0
  Ga  Ga1  1  0.12  0.0  0.92  1.0
  Se  Se2  1  0.0  0.0  0.0  1.0

data_SrGa2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.99
_cell_length_b   5.99
_cell_length_c   6.56
_cell_angle_alpha   90.0
_cell_angle_beta   117.17
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   SrGa2Se
_chemical_formula_sum   'Sr2 Ga4 Se2'
_cell_volume   209.5
_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  0.34  0.5  0.84  1.0
  Ga  Ga1  4  0.36  0.44  0.8  1.0
  Se  Se2  2  0.0  0.0  0.0  1.0

Sr Ga Ga Se
SrGa2Se crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two SrGa2Se clusters. Sr(1) is bonded in a distorted L-shaped geometry to two equivalent Ga(1) and one Se(1) atom. Both Sr(1)-Ga(1) bond lengths are 0.48 Å. The Sr(1)-Se(1) bond length is 1.07 Å. Ga(1) is bonded in a single-bond geometry to one Sr(1) atom. Se(1) is bonded in a distorted single-bond geometry to one Sr(1) atom.