data_Sr2PSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.98
_cell_length_b   5.98
_cell_length_c   3.7
_cell_angle_alpha   102.14
_cell_angle_beta   102.14
_cell_angle_gamma   104.34
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr2PSe
_chemical_formula_sum   'Sr2 P1 Se1'
_cell_volume   120.54
_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
  Sr  Sr2  1  0.2  0.64  0.74  1.0
  Sr  Sr3  1  0.2  0.36  0.74  1.0
  P  P0  1  0.0  0.0  0.0  1.0
  Se  Se1  1  0.67  0.0  0.0  1.0

data_Sr2PSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.7
_cell_length_b   5.98
_cell_length_c   5.98
_cell_angle_alpha   104.34
_cell_angle_beta   102.14
_cell_angle_gamma   102.14
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr2PSe
_chemical_formula_sum   'Sr2 P1 Se1'
_cell_volume   120.54
_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
  Sr  Sr0  1  0.74  0.2  0.36  1.0
  Sr  Sr1  1  0.74  0.2  0.64  1.0
  P  P2  1  0.0  0.0  0.0  1.0
  Se  Se3  1  0.0  0.67  0.0  1.0

Sr Sr P Se
Sr2PSe crystallizes in the triclinic P1 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a 3-coordinate geometry to one Sr(2), one P(1), and one Se(1) atom. The Sr(1)-Sr(2) bond length is 1.65 Å. The Sr(1)-P(1) bond length is 2.82 Å. The Sr(1)-Se(1) bond length is 2.91 Å. In the second Sr site, Sr(2) is bonded in a 3-coordinate geometry to one Sr(1) and two equivalent P(1) atoms. There is one shorter (2.67 Å) and one longer (2.91 Å) Sr(2)-P(1) bond length. P(1) is bonded in a distorted rectangular see-saw-like geometry to one Sr(1), two equivalent Sr(2), and one Se(1) atom. The P(1)-Se(1) bond length is 1.98 Å. Se(1) is bonded in a distorted bent 150 degrees geometry to one Sr(1) and one P(1) atom.