data_HfTi2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.19
_cell_length_b   9.19
_cell_length_c   9.19
_cell_angle_alpha   18.96
_cell_angle_beta   18.96
_cell_angle_gamma   18.96
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfTi2Si
_chemical_formula_sum   'Hf1 Ti2 Si1'
_cell_volume   71.54
_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
  Hf  Hf0  1  0.0  0.0  0.53  1.0
  Ti  Ti2  1  0.0  0.0  0.12  1.0
  Ti  Ti3  1  0.0  0.0  0.94  1.0
  Si  Si1  1  0.0  0.0  0.0  1.0

data_HfTi2Si
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.24
_cell_length_b   3.03
_cell_length_c   9.19
_cell_angle_alpha   90.0
_cell_angle_beta   100.96
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   HfTi2Si
_chemical_formula_sum   'Hf2 Ti4 Si2'
_cell_volume   143.07
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Hf  Hf0  2  0.0  0.0  0.47  1.0
  Ti  Ti1  2  0.0  0.0  0.06  1.0
  Ti  Ti2  2  0.0  0.0  0.88  1.0
  Si  Si3  2  0.0  0.0  0.0  1.0

Hf Ti Ti Si
Hf(Ti)2Si crystallizes in the monoclinic Cm space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to six Hf(1,1); one Ti(1); and one Ti(2) atom to form a mixture of corner and edge-sharing HfHf6Ti2 hexagonal bipyramids. All Hf(1)-Hf(1,1) bond lengths are 3.03 Å. The Hf(1)-Ti(1) bond length is 3.74 Å. The Hf(1)-Ti(2) bond length is 3.74 Å. In the second Hf site, Hf(1) is bonded to six Hf(1,1); one Ti(1); and one Ti(2) atom to form a mixture of corner and edge-sharing HfHf6Ti2 hexagonal bipyramids. Both Hf(1)-Hf(1) bond lengths are 3.03 Å. The Hf(1)-Ti(1) bond length is 3.74 Å. The Hf(1)-Ti(2) bond length is 3.74 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a single-bond geometry to one Hf(1) and one Si(1) atom. The Ti(1)-Si(1) bond length is 1.14 Å. In the second Ti site, Ti(2) is bonded in a single-bond geometry to one Hf(1) and one Si(1) atom. The Ti(2)-Si(1) bond length is 0.56 Å. Si(1) is bonded in a linear geometry to one Ti(1) and one Ti(2) atom.