The crystal structure described by Ni3Si crystallizes in the trigonal R-3m space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent Ni(2), six equivalent Ni(1), and three equivalent Si(1) atoms to form NiSi3Ni9 cuboctahedra that share corners with twelve equivalent Ni(1)Si3Ni9 cuboctahedra, edges with six equivalent Ni(2)Ni12 cuboctahedra, edges with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with twelve equivalent Ni(1)Si3Ni9 cuboctahedra, faces with six equivalent Ni(2)Ni12 cuboctahedra, faces with six equivalent Ni(1)Si3Ni9 cuboctahedra, and faces with six equivalent Si(1)Si6Ni6 cuboctahedra. In the second Ni site, Ni(2) is bonded to six equivalent Ni(1) and six equivalent Ni(2) atoms to form NiNi12 cuboctahedra that share corners with six equivalent Ni(2)Ni12 cuboctahedra, corners with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with six equivalent Ni(2)Ni12 cuboctahedra, edges with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with twelve equivalent Ni(1)Si3Ni9 cuboctahedra, faces with six equivalent Ni(2)Ni12 cuboctahedra, and faces with twelve equivalent Ni(1)Si3Ni9 cuboctahedra. Si(1) is bonded to six equivalent Ni(1) and six equivalent Si(1) atoms to form SiSi6Ni6 cuboctahedra that share corners with six equivalent Ni(2)Ni12 cuboctahedra, corners with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with six equivalent Ni(2)Ni12 cuboctahedra, edges with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with twelve equivalent Ni(1)Si3Ni9 cuboctahedra, faces with six equivalent Si(1)Si6Ni6 cuboctahedra, and faces with twelve equivalent Ni(1)Si3Ni9 cuboctahedra. is represented by the CIF file [CIF]
data_SiNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.806
_cell_length_b   7.806
_cell_length_c   7.806
_cell_angle_alpha   19.066
_cell_angle_beta   19.066
_cell_angle_gamma   19.066
_symmetry_Int_Tables_number   1
_cell_volume   44.361
_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
  Si  Si0  1  0.000  0.000  0.000  1.0
  Ni  Ni1  1  0.255  0.255  0.255  1.0
  Ni  Ni2  1  0.500  0.500  0.500  1.0
  Ni  Ni3  1  0.745  0.745  0.745  1.0
[/CIF]
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The crystal structure described by Ni3Si crystallizes in the trigonal R-3m space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent Ni(2), six equivalent Ni(1), and three equivalent Si(1) atoms to form NiSi3Ni9 cuboctahedra that share corners with twelve equivalent Ni(1)Si3Ni9 cuboctahedra, edges with six equivalent Ni(2)Ni12 cuboctahedra, edges with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with twelve equivalent Ni(1)Si3Ni9 cuboctahedra, faces with six equivalent Ni(2)Ni12 cuboctahedra, faces with six equivalent Ni(1)Si3Ni9 cuboctahedra, and faces with six equivalent Si(1)Si6Ni6 cuboctahedra. In the second Ni site, Ni(2) is bonded to six equivalent Ni(1) and six equivalent Ni(2) atoms to form NiNi12 cuboctahedra that share corners with six equivalent Ni(2)Ni12 cuboctahedra, corners with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with six equivalent Ni(2)Ni12 cuboctahedra, edges with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with twelve equivalent Ni(1)Si3Ni9 cuboctahedra, faces with six equivalent Ni(2)Ni12 cuboctahedra, and faces with twelve equivalent Ni(1)Si3Ni9 cuboctahedra. Si(1) is bonded to six equivalent Ni(1) and six equivalent Si(1) atoms to form SiSi6Ni6 cuboctahedra that share corners with six equivalent Ni(2)Ni12 cuboctahedra, corners with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with six equivalent Ni(2)Ni12 cuboctahedra, edges with six equivalent Si(1)Si6Ni6 cuboctahedra, edges with twelve equivalent Ni(1)Si3Ni9 cuboctahedra, faces with six equivalent Si(1)Si6Ni6 cuboctahedra, and faces with twelve equivalent Ni(1)Si3Ni9 cuboctahedra. is represented by the CIF file [CIF]
data_SiNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.806
_cell_length_b   7.806
_cell_length_c   7.806
_cell_angle_alpha   19.066
_cell_angle_beta   19.066
_cell_angle_gamma   19.066
_symmetry_Int_Tables_number   1
_cell_volume   44.361
_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
  Si  Si0  1  0.000  0.000  0.000  1.0
  Ni  Ni1  1  0.255  0.255  0.255  1.0
  Ni  Ni2  1  0.500  0.500  0.500  1.0
  Ni  Ni3  1  0.745  0.745  0.745  1.0
[/CIF]
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