data_CsHfSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.1
_cell_length_b   5.1
_cell_length_c   5.1
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CsHfSi2
_chemical_formula_sum   'Cs1 Hf1 Si2'
_cell_volume   94.05
_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
  Cs  Cs0  1  0.0  0.0  0.0  1.0
  Hf  Hf1  1  0.61  0.61  0.61  1.0
  Si  Si2  1  0.41  0.41  0.41  1.0
  Si  Si3  1  0.8  0.8  0.8  1.0

data_CsHfSi2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.1
_cell_length_b   5.1
_cell_length_c   12.5
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CsHfSi2
_chemical_formula_sum   'Cs3 Hf3 Si6'
_cell_volume   282.15
_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
  Cs  Cs0  3  0.0  0.0  0.0  1.0
  Hf  Hf1  3  0.0  0.0  0.39  1.0
  Si  Si2  3  0.0  0.0  0.2  1.0
  Si  Si3  3  0.0  0.0  0.59  1.0

Cs Hf Si Si
Cs Hf Si Si 0 3 - - - 0 3 - - o 0 3 o - - 0 3 - o - 0 1 - - o 0 1 - o - 0 1 o - - 0 2 - o o 0 2 o - o 0 2 o o - 1 2 o o o 1 2 o + o 1 2 + o o 1 2 o o + 1 3 o o o 2 3 - o o 2 3 o - o 2 3 o o - 
CsHfSi2 crystallizes in the trigonal R3m space group. Cs(1) is bonded in a 1-coordinate geometry to one Si(2) and three equivalent Si(1) atoms. The Cs(1)-Si(2) bond length is 2.44 Å. All Cs(1)-Si(1) bond lengths are 3.12 Å. Hf(1) is bonded in a distorted linear geometry to one Si(1) and one Si(2) atom. The Hf(1)-Si(1) bond length is 2.44 Å. The Hf(1)-Si(2) bond length is 2.44 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to three equivalent Cs(1) and one Hf(1) atom to form distorted corner-sharing SiCs3Hf tetrahedra. In the second Si site, Si(2) is bonded in a linear geometry to one Cs(1) and one Hf(1) atom.