data_Sc3Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.6
_cell_length_b   5.6
_cell_length_c   5.6
_cell_angle_alpha   116.08
_cell_angle_beta   116.08
_cell_angle_gamma   116.08
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sc3Se
_chemical_formula_sum   'Sc3 Se1'
_cell_volume   87.64
_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
  Sc  Sc0  1  0.37  0.63  0.12  1.0
  Sc  Sc1  1  0.63  0.63  0.12  1.0
  Sc  Sc2  1  0.0  0.74  0.12  1.0
  Se  Se3  1  0.0  0.0  0.0  1.0

data_Sc3Se
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.37
_cell_length_b   5.6
_cell_length_c   5.6
_cell_angle_alpha   116.08
_cell_angle_beta   101.57
_cell_angle_gamma   101.57
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sc3Se
_chemical_formula_sum   'Sc3 Se1'
_cell_volume   87.64
_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
  Sc  Sc0  1  0.12  0.5  0.49  1.0
  Sc  Sc1  1  0.12  0.75  0.49  1.0
  Sc  Sc2  1  0.12  0.12  0.38  1.0
  Se  Se3  1  0.0  0.0  0.0  1.0

Sc Sc Sc Se
Sc Sc Sc Se 0 1 o o o 1 2 + o o 2 3 o + o 
Sc3Se crystallizes in the triclinic P1 space group. There are three inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 4-coordinate geometry to one Sc(2), one Sc(3), and two equivalent Se(1) atoms. The Sc(1)-Sc(2) bond length is 1.41 Å. The Sc(1)-Sc(3) bond length is 2.43 Å. There is one shorter (2.72 Å) and one longer (3.20 Å) Sc(1)-Se(1) bond length. In the second Sc site, Sc(2) is bonded in a 2-coordinate geometry to one Sc(1) and one Sc(3) atom. The Sc(2)-Sc(3) bond length is 1.90 Å. In the third Sc site, Sc(3) is bonded in a single-bond geometry to one Sc(1), one Sc(2), and one Se(1) atom. The Sc(3)-Se(1) bond length is 1.85 Å. Se(1) is bonded in a distorted single-bond geometry to one Sc(3) and two equivalent Sc(1) atoms.