data_LaSi2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.97
_cell_length_b   4.97
_cell_length_c   4.97
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   LaSi2As
_chemical_formula_sum   'La1 Si2 As1'
_cell_volume   86.88
_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
  La  La1  1  0.27  0.27  0.27  1.0
  Si  Si2  1  0.0  0.0  0.0  1.0
  Si  Si3  1  0.76  0.76  0.76  1.0
  As  As0  1  0.52  0.52  0.52  1.0

data_LaSi2As
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.97
_cell_length_b   4.97
_cell_length_c   12.18
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   LaSi2As
_chemical_formula_sum   'La3 Si6 As3'
_cell_volume   260.64
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  La  La0  3  0.0  0.0  0.73  1.0
  Si  Si1  3  0.0  0.0  0.0  1.0
  Si  Si2  3  0.0  0.0  0.24  1.0
  As  As3  3  0.0  0.0  0.48  1.0

La Si Si As
La Si Si As 0 1 o o o 0 1 o o + 0 1 o + o 0 1 + o o 0 3 o - o 0 3 - o o 0 3 o o - 0 3 o o o 0 2 - - o 0 2 - o - 0 2 - o o 0 2 o - - 0 2 o - o 0 2 o o - 1 2 - - - 1 2 - - o 1 2 o - - 1 2 - o - 1 3 - - o 1 3 - o - 1 3 - o o 1 3 o - - 1 3 o - o 1 3 o o - 2 3 o o o 2 3 o o + 2 3 + o o 2 3 o + o 
LaSi2As crystallizes in the trigonal R3m space group. La(1) is bonded in a 8-coordinate geometry to four equivalent Si(1) and four equivalent As(1) atoms. There are three shorter (2.96 Å) and one longer (3.32 Å) La(1)-Si(1) bond length. There is one shorter (2.95 Å) and three longer (3.08 Å) La(1)-As(1) bond lengths. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to four equivalent La(1) atoms to form distorted corner-sharing SiLa4 tetrahedra. In the second Si site, Si(2) is bonded in a 1-coordinate geometry to one As(1) atom. The Si(2)-As(1) bond length is 2.95 Å. As(1) is bonded in a 5-coordinate geometry to four equivalent La(1) and one Si(2) atom.