data_CaGaSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.09
_cell_length_b   5.09
_cell_length_c   5.09
_cell_angle_alpha   121.86
_cell_angle_beta   118.57
_cell_angle_gamma   89.65
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaGaSe2
_chemical_formula_sum   'Ca1 Ga1 Se2'
_cell_volume   92.65
_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
  Ca  Ca0  1  0.0  0.0  0.0  1.0
  Ga  Ga1  1  0.0  0.0  0.61  1.0
  Se  Se2  1  0.0  0.6  0.72  1.0
  Se  Se3  1  0.47  0.0  0.89  1.0

data_CaGaSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.94
_cell_length_b   5.09
_cell_length_c   5.09
_cell_angle_alpha   61.43
_cell_angle_beta   60.93
_cell_angle_gamma   60.93
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaGaSe2
_chemical_formula_sum   'Ca1 Ga1 Se2'
_cell_volume   92.65
_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
  Ca  Ca0  1  0.0  0.0  0.0  1.0
  Ga  Ga1  1  0.0  0.0  0.61  1.0
  Se  Se2  1  0.0  0.53  0.89  1.0
  Se  Se3  1  0.6  0.0  0.12  1.0

Ca Ga Se Se
Ca Ga Se Se 0 2 o - - 0 1 o o - 0 3 - o - 1 2 o - o 1 3 o o o 2 3 o + o 
CaGaSe2 crystallizes in the triclinic P1 space group. Ca(1) is bonded in a 3-coordinate geometry to two equivalent Ga(1), one Se(1), and one Se(2) atom. There is one shorter (2.00 Å) and one longer (3.09 Å) Ca(1)-Ga(1) bond length. The Ca(1)-Se(1) bond length is 1.77 Å. The Ca(1)-Se(2) bond length is 2.47 Å. Ga(1) is bonded in a 5-coordinate geometry to two equivalent Ca(1), one Se(2), and two equivalent Se(1) atoms. The Ga(1)-Se(2) bond length is 2.12 Å. There is one shorter (2.40 Å) and one longer (2.78 Å) Ga(1)-Se(1) bond length. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted single-bond geometry to one Ca(1) and two equivalent Ga(1) atoms. In the second Se site, Se(2) is bonded in a distorted bent 150 degrees geometry to one Ca(1) and one Ga(1) atom.