The structure described by SrGa2Se4 crystallizes in the orthorhombic Cccm space group. Sr(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. Ga(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form edge-sharing GaSe4 tetrahedra. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded to two equivalent Sr(1) and two equivalent Ga(1) atoms to form a mixture of distorted edge and corner-sharing SeSr2Ga2 trigonal pyramids. In the second Se site, Se(1) is bonded to two equivalent Sr(1) and two equivalent Ga(1) atoms to form a mixture of edge and corner-sharing SeSr2Ga2 trigonal pyramids. is represented by the CIF file [CIF]
data_Sr(GaSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.324
_cell_length_b   6.324
_cell_length_c   11.028
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.354
_symmetry_Int_Tables_number   1
_cell_volume   380.591
_cell_formula_units_Z   2
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  Sr0  1  0.500  0.500  0.750  1.0
  Sr  Sr1  1  0.500  0.500  0.250  1.0
  Ga  Ga2  1  0.762  0.240  0.500  1.0
  Ga  Ga3  1  0.238  0.760  0.500  1.0
  Ga  Ga4  1  0.760  0.238  0.000  1.0
  Ga  Ga5  1  0.240  0.762  0.000  1.0
  Se  Se6  1  0.349  0.184  0.500  1.0
  Se  Se7  1  0.651  0.816  0.500  1.0
  Se  Se8  1  0.816  0.651  0.000  1.0
  Se  Se9  1  0.184  0.349  0.000  1.0
  Se  Se10  1  0.500  0.000  0.833  1.0
  Se  Se11  1  0.000  0.500  0.667  1.0
  Se  Se12  1  0.500  0.000  0.167  1.0
  Se  Se13  1  0.000  0.500  0.333  1.0
[/CIF]
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The structure described by SrGa2Se4 crystallizes in the orthorhombic Cccm space group. Sr(1) is bonded in a 8-coordinate geometry to four equivalent Se(1) and four equivalent Se(2) atoms. Ga(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form edge-sharing GaSe4 tetrahedra. There are two inequivalent Se sites. In the first Se site, Se(2) is bonded to two equivalent Sr(1) and two equivalent Ga(1) atoms to form a mixture of distorted edge and corner-sharing SeSr2Ga2 trigonal pyramids. In the second Se site, Se(1) is bonded to two equivalent Sr(1) and two equivalent Ga(1) atoms to form a mixture of edge and corner-sharing SeSr2Ga2 trigonal pyramids. is represented by the CIF file [CIF]
data_Sr(GaSe2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.324
_cell_length_b   6.324
_cell_length_c   11.028
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.354
_symmetry_Int_Tables_number   1
_cell_volume   380.591
_cell_formula_units_Z   2
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  Sr0  1  0.500  0.500  0.750  1.0
  Sr  Sr1  1  0.500  0.500  0.250  1.0
  Ga  Ga2  1  0.762  0.240  0.500  1.0
  Ga  Ga3  1  0.238  0.760  0.500  1.0
  Ga  Ga4  1  0.760  0.238  0.000  1.0
  Ga  Ga5  1  0.240  0.762  0.000  1.0
  Se  Se6  1  0.349  0.184  0.500  1.0
  Se  Se7  1  0.651  0.816  0.500  1.0
  Se  Se8  1  0.816  0.651  0.000  1.0
  Se  Se9  1  0.184  0.349  0.000  1.0
  Se  Se10  1  0.500  0.000  0.833  1.0
  Se  Se11  1  0.000  0.500  0.667  1.0
  Se  Se12  1  0.500  0.000  0.167  1.0
  Se  Se13  1  0.000  0.500  0.333  1.0
[/CIF]
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