data_CaOs2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.56
_cell_length_b   4.56
_cell_length_c   4.56
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaOs2Se
_chemical_formula_sum   'Ca1 Os2 Se1'
_cell_volume   66.93
_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
  Os  Os1  1  0.61  0.61  0.61  1.0
  Os  Os2  1  0.83  0.83  0.83  1.0
  Se  Se3  1  0.22  0.22  0.22  1.0

data_CaOs2Se
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.56
_cell_length_b   4.56
_cell_length_c   11.16
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CaOs2Se
_chemical_formula_sum   'Ca3 Os6 Se3'
_cell_volume   200.78
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  Os  Os1  3  0.0  0.0  0.17  1.0
  Os  Os2  3  0.0  0.0  0.39  1.0
  Se  Se3  3  0.0  0.0  0.78  1.0

Ca Os Os Se
CaOs2Se crystallizes in the trigonal R3m space group. Ca(1) is bonded in a 1-coordinate geometry to one Os(2), three equivalent Os(1), and four equivalent Se(1) atoms. The Ca(1)-Os(2) bond length is 1.86 Å. All Ca(1)-Os(1) bond lengths are 2.70 Å. There is one shorter (2.48 Å) and three longer (2.91 Å) Ca(1)-Se(1) bond lengths. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded in a 7-coordinate geometry to three equivalent Ca(1), one Os(2), and three equivalent Se(1) atoms. The Os(1)-Os(2) bond length is 2.48 Å. All Os(1)-Se(1) bond lengths are 2.70 Å. In the second Os site, Os(2) is bonded in a single-bond geometry to one Ca(1), one Os(1), and three equivalent Se(1) atoms. All Os(2)-Se(1) bond lengths are 2.70 Å. Se(1) is bonded in a distorted single-bond geometry to four equivalent Ca(1), three equivalent Os(1), and three equivalent Os(2) atoms.