The structure described by La3NiSi3 crystallizes in the orthorhombic Imm2 space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. In the second La site, La(2) is bonded in a 7-coordinate geometry to two equivalent Ni(1), one Si(2), and four equivalent Si(1) atoms. In the third La site, La(3) is bonded to four equivalent Ni(1), two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms to form a mixture of edge and face-sharing LaSi8Ni4 cuboctahedra. Ni(1) is bonded in a 9-coordinate geometry to two equivalent La(2), four equivalent La(3), one Si(3), and two equivalent Si(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one La(1), two equivalent La(3), four equivalent La(2), and two equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one La(2), two equivalent La(3), four equivalent La(1), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent La(1), four equivalent La(3), one Ni(1), and two equivalent Si(2) atoms. is represented by the CIF file [CIF]
data_La3Si3Ni
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.609
_cell_length_b   9.609
_cell_length_c   9.609
_cell_angle_alpha   155.459
_cell_angle_beta   153.606
_cell_angle_gamma   36.349
_symmetry_Int_Tables_number   1
_cell_volume   163.609
_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  La0  1  0.816  0.316  0.500  1.0
  La  La1  1  0.181  0.681  0.500  1.0
  La  La2  1  0.001  0.001  0.000  1.0
  Si  Si3  1  0.633  0.133  0.500  1.0
  Si  Si4  1  0.363  0.863  0.500  1.0
  Si  Si5  1  0.440  0.440  0.000  1.0
  Ni  Ni6  1  0.566  0.566  0.000  1.0
[/CIF]
.
The structure described by La3NiSi3 crystallizes in the orthorhombic Imm2 space group. There are three inequivalent La sites. In the first La site, La(1) is bonded in a 7-coordinate geometry to one Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. In the second La site, La(2) is bonded in a 7-coordinate geometry to two equivalent Ni(1), one Si(2), and four equivalent Si(1) atoms. In the third La site, La(3) is bonded to four equivalent Ni(1), two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms to form a mixture of edge and face-sharing LaSi8Ni4 cuboctahedra. Ni(1) is bonded in a 9-coordinate geometry to two equivalent La(2), four equivalent La(3), one Si(3), and two equivalent Si(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one La(1), two equivalent La(3), four equivalent La(2), and two equivalent Ni(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one La(2), two equivalent La(3), four equivalent La(1), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent La(1), four equivalent La(3), one Ni(1), and two equivalent Si(2) atoms. is represented by the CIF file [CIF]
data_La3Si3Ni
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.609
_cell_length_b   9.609
_cell_length_c   9.609
_cell_angle_alpha   155.459
_cell_angle_beta   153.606
_cell_angle_gamma   36.349
_symmetry_Int_Tables_number   1
_cell_volume   163.609
_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  La0  1  0.816  0.316  0.500  1.0
  La  La1  1  0.181  0.681  0.500  1.0
  La  La2  1  0.001  0.001  0.000  1.0
  Si  Si3  1  0.633  0.133  0.500  1.0
  Si  Si4  1  0.363  0.863  0.500  1.0
  Si  Si5  1  0.440  0.440  0.000  1.0
  Ni  Ni6  1  0.566  0.566  0.000  1.0
[/CIF]
.