data_KYSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.06
_cell_length_b   6.06
_cell_length_c   3.53
_cell_angle_alpha   101.78
_cell_angle_beta   101.78
_cell_angle_gamma   105.6
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KYSe2
_chemical_formula_sum   'K1 Y1 Se2'
_cell_volume   117.83
_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
  K  K0  1  0.0  0.0  0.0  1.0
  Y  Y3  1  0.67  0.0  0.0  1.0
  Se  Se1  1  0.24  0.42  0.66  1.0
  Se  Se2  1  0.24  0.58  0.66  1.0

data_KYSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.53
_cell_length_b   6.06
_cell_length_c   6.06
_cell_angle_alpha   105.6
_cell_angle_beta   101.78
_cell_angle_gamma   101.78
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KYSe2
_chemical_formula_sum   'K1 Y1 Se2'
_cell_volume   117.83
_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
  K  K0  1  0.0  0.0  0.0  1.0
  Y  Y1  1  0.0  0.67  0.0  1.0
  Se  Se2  1  0.66  0.24  0.58  1.0
  Se  Se3  1  0.66  0.24  0.42  1.0

K Y Se Se
K Y Se Se 0 1 - o o 2 3 o o o 
KYSe2 crystallizes in the triclinic P1 space group. K(1) is bonded in a 4-coordinate geometry to one Y(1), one Se(2), and two equivalent Se(1) atoms. The K(1)-Y(1) bond length is 2.02 Å. The K(1)-Se(2) bond length is 3.35 Å. There is one shorter (2.86 Å) and one longer (3.13 Å) K(1)-Se(1) bond length. Y(1) is bonded in a bent 120 degrees geometry to one K(1) and one Se(2) atom. The Y(1)-Se(2) bond length is 2.92 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 3-coordinate geometry to two equivalent K(1) and one Se(2) atom. The Se(1)-Se(2) bond length is 1.03 Å. In the second Se site, Se(2) is bonded in a 3-coordinate geometry to one K(1), one Y(1), and one Se(1) atom.