data_Na(LaSi)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.74
_cell_length_b   6.74
_cell_length_c   6.74
_cell_angle_alpha   134.61
_cell_angle_beta   134.61
_cell_angle_gamma   66.14
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na(LaSi)2
_chemical_formula_sum   'Na1 La2 Si2'
_cell_volume   153.07
_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
  Na  Na2  1  0.0  0.0  0.0  1.0
  La  La0  1  0.0  0.6  0.83  1.0
  La  La1  1  0.6  0.0  0.83  1.0
  Si  Si3  1  0.0  0.0  0.83  1.0
  Si  Si4  1  0.0  0.0  0.47  1.0

data_Na(LaSi)2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.36
_cell_length_b   7.36
_cell_length_c   6.74
_cell_angle_alpha   90.0
_cell_angle_beta   123.07
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na(LaSi)2
_chemical_formula_sum   'Na2 La4 Si4'
_cell_volume   306.15
_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
  Na  Na0  2  0.0  0.0  0.0  1.0
  La  La1  4  0.2  0.2  0.22  1.0
  Si  Si2  2  0.0  0.0  0.47  1.0
  Si  Si3  2  0.0  0.0  0.83  1.0

Na La La Si Si
Na La La Si Si 0 3 o o - 0 1 o - - 0 2 - o - 0 4 o o o 1 4 o o o 1 4 o + + 2 4 + o + 2 4 o o o 3 4 o o o 
Na(LaSi)2 crystallizes in the monoclinic Cm space group. Na(1) is bonded in a distorted single-bond geometry to two equivalent La(1), one Si(1), and one Si(2) atom. Both Na(1)-La(1) bond lengths are 2.04 Å. The Na(1)-Si(1) bond length is 1.13 Å. The Na(1)-Si(2) bond length is 3.17 Å. La(1) is bonded in a 3-coordinate geometry to one Na(1) and two equivalent Si(2) atoms. There is one shorter (2.93 Å) and one longer (3.12 Å) La(1)-Si(2) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a single-bond geometry to one Na(1) and one Si(2) atom. The Si(1)-Si(2) bond length is 2.44 Å. In the second Si site, Si(2) is bonded in a 6-coordinate geometry to one Na(1), four equivalent La(1), and one Si(1) atom.