data_CaSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.55
_cell_length_b   3.55
_cell_length_c   4.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaSi
_chemical_formula_sum   'Ca1 Si1'
_cell_volume   50.01
_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  0.78  0.03  0.29  1.0
  Si  Si1  1  0.0  0.0  0.0  1.0

data_CaSi
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.55
_cell_length_b   3.55
_cell_length_c   4.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaSi
_chemical_formula_sum   'Ca1 Si1'
_cell_volume   50.01
_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  0.78  0.03  0.29  1.0
  Si  Si1  1  0.0  0.0  0.0  1.0

Ca Si
Ca Si 0 1 + o o 
CaSi crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one calcium silicide (casi) molecule. Ca(1) is bonded in a single-bond geometry to one Si(1) atom. The Ca(1)-Si(1) bond length is 1.56 Å. Si(1) is bonded in a single-bond geometry to one Ca(1) atom.