data_CaSe3Cl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.04
_cell_length_b   5.04
_cell_length_c   5.04
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaSe3Cl
_chemical_formula_sum   'Ca1 Se3 Cl1'
_cell_volume   128.0
_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  0.52  0.52  0.52  1.0
  Se  Se1  1  0.0  0.52  0.0  1.0
  Se  Se2  1  0.0  0.0  0.52  1.0
  Se  Se3  1  0.52  0.0  0.0  1.0
  Cl  Cl4  1  0.0  0.0  0.0  1.0

data_CaSe3Cl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.13
_cell_length_b   7.13
_cell_length_c   8.73
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CaSe3Cl
_chemical_formula_sum   'Ca3 Se9 Cl3'
_cell_volume   384.01
_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  0.52  1.0
  Se  Se1  9  0.01  0.51  0.51  1.0
  Cl  Cl2  3  0.0  0.0  0.0  1.0

Ca Se Se Se Cl
CaSe3Cl is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Ca(1) is bonded to twelve equivalent Se(1) atoms to form distorted CaSe12 cuboctahedra that share corners with twelve equivalent Ca(1)Se12 cuboctahedra, faces with six equivalent Ca(1)Se12 cuboctahedra, and faces with eight equivalent Cl(1)Se6 octahedra. There are a spread of Ca(1)-Se(1) bond distances ranging from 3.42-3.71 Å. Se(1) is bonded in a 2-coordinate geometry to four equivalent Ca(1) and two equivalent Cl(1) atoms. There is one shorter (2.42 Å) and one longer (2.62 Å) Se(1)-Cl(1) bond length. Cl(1) is bonded to six equivalent Se(1) atoms to form ClSe6 octahedra that share corners with six equivalent Cl(1)Se6 octahedra and faces with eight equivalent Ca(1)Se12 cuboctahedra. The corner-sharing octahedra are not tilted.