The compound described by Sr2Si crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a trigonal planar geometry to three equivalent Si(1) atoms. In the second Sr site, Sr(2) is bonded to six equivalent Si(1) atoms to form a mixture of distorted face, corner, and edge-sharing SrSi6 octahedra. The corner-sharing octahedral tilt angles are 51°. Si(1) is bonded in a distorted trigonal planar geometry to three equivalent Sr(1) and six equivalent Sr(2) atoms. is represented by the CIF card [CIF]
data_Sr2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.414
_cell_length_b   5.414
_cell_length_c   7.551
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   191.662
_cell_formula_units_Z   2
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  0.333  0.667  0.750  1.0
  Sr  Sr1  1  0.667  0.333  0.250  1.0
  Sr  Sr2  1  0.000  0.000  0.500  1.0
  Sr  Sr3  1  0.000  0.000  0.000  1.0
  Si  Si4  1  0.667  0.333  0.750  1.0
  Si  Si5  1  0.333  0.667  0.250  1.0
[/CIF]
.
The compound described by Sr2Si crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a trigonal planar geometry to three equivalent Si(1) atoms. In the second Sr site, Sr(2) is bonded to six equivalent Si(1) atoms to form a mixture of distorted face, corner, and edge-sharing SrSi6 octahedra. The corner-sharing octahedral tilt angles are 51°. Si(1) is bonded in a distorted trigonal planar geometry to three equivalent Sr(1) and six equivalent Sr(2) atoms. is represented by the CIF card [CIF]
data_Sr2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.414
_cell_length_b   5.414
_cell_length_c   7.551
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   191.662
_cell_formula_units_Z   2
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  0.333  0.667  0.750  1.0
  Sr  Sr1  1  0.667  0.333  0.250  1.0
  Sr  Sr2  1  0.000  0.000  0.500  1.0
  Sr  Sr3  1  0.000  0.000  0.000  1.0
  Si  Si4  1  0.667  0.333  0.750  1.0
  Si  Si5  1  0.333  0.667  0.250  1.0
[/CIF]
.