data_Sc2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.58
_cell_length_b   5.58
_cell_length_c   9.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sc2Si
_chemical_formula_sum   'Sc8 Si4'
_cell_volume   242.93
_cell_formula_units_Z   4
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
  Sc  Sc0  1  0.0  0.0  0.51  1.0
  Sc  Sc1  1  0.0  0.0  0.0  1.0
  Sc  Sc2  1  0.34  1.0  0.76  1.0
  Sc  Sc3  1  0.45  0.84  0.25  1.0
  Sc  Sc4  1  0.66  1.0  0.76  1.0
  Sc  Sc5  1  0.0  0.67  0.76  1.0
  Sc  Sc6  1  0.79  0.16  0.25  1.0
  Sc  Sc7  1  0.13  0.84  0.25  1.0
  Si  Si8  1  0.79  0.61  0.04  1.0
  Si  Si9  1  0.0  0.22  0.53  1.0
  Si  Si10  1  0.0  0.22  0.97  1.0
  Si  Si11  1  0.79  0.61  0.48  1.0

data_Sc2Si
_symmetry_space_group_name_H-M   Pm
_cell_length_a   5.58
_cell_length_b   9.01
_cell_length_c   5.58
_cell_angle_alpha   90.0
_cell_angle_beta   120.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   Sc2Si
_chemical_formula_sum   'Sc8 Si4'
_cell_volume   242.93
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '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
  Sc  Sc0  2  0.0  0.25  0.0  1.0
  Sc  Sc1  1  -0.0  0.0  0.67  1.0
  Sc  Sc2  1  0.13  0.5  0.84  1.0
  Sc  Sc3  1  0.34  0.0  1.0  1.0
  Sc  Sc4  1  0.45  0.5  0.84  1.0
  Sc  Sc5  1  0.66  0.0  1.0  1.0
  Sc  Sc6  1  0.79  0.5  0.16  1.0
  Si  Si7  2  -0.0  0.22  0.22  1.0
  Si  Si8  2  0.79  0.28  0.61  1.0

Sc Sc Sc Sc Sc Sc Sc Sc Si Si Si Si
Sc2Si crystallizes in the triclinic P1 space group. There are eight inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. The Sc(1)-Si(2) bond length is 1.26 Å. The Sc(1)-Si(4) bond length is 1.90 Å. In the second Sc site, Sc(2) is bonded in a distorted bent 150 degrees geometry to one Si(1) and one Si(3) atom. The Sc(2)-Si(1) bond length is 1.92 Å. The Sc(2)-Si(3) bond length is 1.26 Å. In the third Sc site, Sc(3) is bonded in a distorted bent 120 degrees geometry to one Sc(5) and one Sc(6) atom. The Sc(3)-Sc(5) bond length is 1.76 Å. The Sc(3)-Sc(6) bond length is 1.86 Å. In the fourth Sc site, Sc(4) is bonded in a 4-coordinate geometry to one Sc(7), one Sc(8), one Si(1), and one Si(4) atom. The Sc(4)-Sc(7) bond length is 1.86 Å. The Sc(4)-Sc(8) bond length is 1.76 Å. The Sc(4)-Si(1) bond length is 3.36 Å. The Sc(4)-Si(4) bond length is 3.42 Å. In the fifth Sc site, Sc(5) is bonded in a distorted trigonal planar geometry to one Sc(3), one Si(2), and one Si(3) atom. The Sc(5)-Si(2) bond length is 2.62 Å. The Sc(5)-Si(3) bond length is 2.55 Å. In the sixth Sc site, Sc(6) is bonded in a 5-coordinate geometry to one Sc(3), one Si(1), one Si(2), one Si(3), and one Si(4) atom. The Sc(6)-Si(1) bond length is 2.75 Å. The Sc(6)-Si(2) bond length is 3.22 Å. The Sc(6)-Si(3) bond length is 3.16 Å. The Sc(6)-Si(4) bond length is 2.75 Å. In the seventh Sc site, Sc(7) is bonded in a 5-coordinate geometry to one Sc(4), one Si(1), one Si(2), one Si(3), and one Si(4) atom. The Sc(7)-Si(1) bond length is 3.16 Å. The Sc(7)-Si(2) bond length is 2.75 Å. The Sc(7)-Si(3) bond length is 2.75 Å. The Sc(7)-Si(4) bond length is 3.22 Å. In the eighth Sc site, Sc(8) is bonded in a 3-coordinate geometry to one Sc(4), one Si(1), and one Si(4) atom. The Sc(8)-Si(1) bond length is 2.55 Å. The Sc(8)-Si(4) bond length is 2.62 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 1-coordinate geometry to one Sc(2), one Sc(4), one Sc(6), one Sc(7), and one Sc(8) atom. In the second Si site, Si(2) is bonded in a single-bond geometry to one Sc(1), one Sc(5), one Sc(6), and one Sc(7) atom. In the third Si site, Si(3) is bonded in a distorted single-bond geometry to one Sc(2), one Sc(5), one Sc(6), and one Sc(7) atom. In the fourth Si site, Si(4) is bonded in a distorted single-bond geometry to one Sc(1), one Sc(4), one Sc(6), one Sc(7), and one Sc(8) atom.