data_Na2LaSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.9
_cell_length_b   11.9
_cell_length_c   11.9
_cell_angle_alpha   15.98
_cell_angle_beta   15.98
_cell_angle_gamma   15.98
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2LaSi
_chemical_formula_sum   'Na2 La1 Si1'
_cell_volume   111.28
_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  Na1  1  0.0  0.0  0.28  1.0
  Na  Na2  1  0.0  0.0  0.95  1.0
  La  La0  1  0.0  0.0  0.62  1.0
  Si  Si3  1  0.0  0.0  0.0  1.0

data_Na2LaSi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.73
_cell_length_b   3.31
_cell_length_c   11.9
_cell_angle_alpha   90.0
_cell_angle_beta   99.24
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2LaSi
_chemical_formula_sum   'Na4 La2 Si2'
_cell_volume   222.56
_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  0.05  1.0
  Na  Na1  2  0.0  0.0  0.72  1.0
  La  La2  2  -0.0  0.0  0.38  1.0
  Si  Si3  2  0.0  0.0  0.0  1.0

Na Na La Si
Na2LaSi crystallizes in the monoclinic Cm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted single-bond geometry to one La(1) and one Si(1) atom. The Na(1)-La(1) bond length is 3.95 Å. The Na(1)-Si(1) bond length is 3.38 Å. In the second Na site, Na(2) is bonded in a single-bond geometry to one La(1) and one Si(1) atom. The Na(2)-La(1) bond length is 3.95 Å. The Na(2)-Si(1) bond length is 0.63 Å. There are two inequivalent La sites. In the first La site, La(1) is bonded to one Na(1); one Na(2); and six La(1,1) atoms to form a mixture of corner and edge-sharing LaNa2La6 hexagonal bipyramids. All La(1)-La(1,1) bond lengths are 3.31 Å. In the second La site, La(1) is bonded to one Na(1); one Na(2); and six La(1,1) atoms to form a mixture of corner and edge-sharing LaNa2La6 hexagonal bipyramids. The La(1)-Na(1) bond length is 3.95 Å. The La(1)-Na(2) bond length is 3.95 Å. Both La(1)-La(1) bond lengths are 3.31 Å. Si(1) is bonded in a single-bond geometry to one Na(1) and one Na(2) atom.