data_Mg2GaSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.14
_cell_length_b   8.14
_cell_length_c   8.14
_cell_angle_alpha   26.09
_cell_angle_beta   26.09
_cell_angle_gamma   26.09
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2GaSe
_chemical_formula_sum   'Mg2 Ga1 Se1'
_cell_volume   91.96
_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
  Mg  Mg1  1  0.0  0.0  0.09  1.0
  Mg  Mg2  1  0.0  0.0  0.59  1.0
  Ga  Ga0  1  0.0  0.0  0.91  1.0
  Se  Se3  1  0.0  0.0  0.77  1.0

data_Mg2GaSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.37
_cell_length_b   3.68
_cell_length_c   8.14
_cell_angle_alpha   90.0
_cell_angle_beta   105.11
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Mg2GaSe
_chemical_formula_sum   'Mg4 Ga2 Se2'
_cell_volume   183.91
_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
  Mg  Mg0  2  0.0  0.0  0.41  1.0
  Mg  Mg1  2  0.0  0.0  0.91  1.0
  Ga  Ga2  2  0.0  0.0  0.09  1.0
  Se  Se3  2  0.0  0.0  0.23  1.0

Mg Mg Ga Se
Mg Mg Ga Se 0 2 o o - 1 3 o o o 2 3 o o o 
Mg2GaSe is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Mg2GaSe clusters. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a single-bond geometry to one Ga(1) atom. The Mg(1)-Ga(1) bond length is 1.41 Å. In the second Mg site, Mg(2) is bonded in a single-bond geometry to one Se(1) atom. The Mg(2)-Se(1) bond length is 1.47 Å. Ga(1) is bonded in a linear geometry to one Mg(1) and one Se(1) atom. The Ga(1)-Se(1) bond length is 1.13 Å. Se(1) is bonded in a linear geometry to one Mg(2) and one Ga(1) atom.