The crystal structure described by Mg2Ni3Si crystallizes in the trigonal R-3m space group. Mg(1) is bonded in a 16-coordinate geometry to four equivalent Mg(1), nine equivalent Ni(1), and three equivalent Si(1) atoms. Ni(1) is bonded to six equivalent Mg(1), four equivalent Ni(1), and two equivalent Si(1) atoms to form NiMg6Si2Ni4 cuboctahedra that share corners with four equivalent Si(1)Mg6Ni6 cuboctahedra, corners with fourteen equivalent Ni(1)Mg6Si2Ni4 cuboctahedra, edges with six equivalent Ni(1)Mg6Si2Ni4 cuboctahedra, faces with six equivalent Si(1)Mg6Ni6 cuboctahedra, and faces with twelve equivalent Ni(1)Mg6Si2Ni4 cuboctahedra. Si(1) is bonded to six equivalent Mg(1) and six equivalent Ni(1) atoms to form SiMg6Ni6 cuboctahedra that share corners with six equivalent Si(1)Mg6Ni6 cuboctahedra, corners with twelve equivalent Ni(1)Mg6Si2Ni4 cuboctahedra, edges with six equivalent Si(1)Mg6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Mg6Si2Ni4 cuboctahedra. is represented by the CIF card [CIF]
data_Mg2SiNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.639
_cell_length_b   4.639
_cell_length_c   4.639
_cell_angle_alpha   64.465
_cell_angle_beta   64.465
_cell_angle_gamma   64.465
_symmetry_Int_Tables_number   1
_cell_volume   77.518
_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
  Mg  Mg0  1  0.125  0.125  0.125  1.0
  Mg  Mg1  1  0.875  0.875  0.875  1.0
  Si  Si2  1  0.500  0.500  0.500  1.0
  Ni  Ni3  1  0.500  0.500  0.000  1.0
  Ni  Ni4  1  0.500  0.000  0.500  1.0
  Ni  Ni5  1  0.000  0.500  0.500  1.0
[/CIF]
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The crystal structure described by Mg2Ni3Si crystallizes in the trigonal R-3m space group. Mg(1) is bonded in a 16-coordinate geometry to four equivalent Mg(1), nine equivalent Ni(1), and three equivalent Si(1) atoms. Ni(1) is bonded to six equivalent Mg(1), four equivalent Ni(1), and two equivalent Si(1) atoms to form NiMg6Si2Ni4 cuboctahedra that share corners with four equivalent Si(1)Mg6Ni6 cuboctahedra, corners with fourteen equivalent Ni(1)Mg6Si2Ni4 cuboctahedra, edges with six equivalent Ni(1)Mg6Si2Ni4 cuboctahedra, faces with six equivalent Si(1)Mg6Ni6 cuboctahedra, and faces with twelve equivalent Ni(1)Mg6Si2Ni4 cuboctahedra. Si(1) is bonded to six equivalent Mg(1) and six equivalent Ni(1) atoms to form SiMg6Ni6 cuboctahedra that share corners with six equivalent Si(1)Mg6Ni6 cuboctahedra, corners with twelve equivalent Ni(1)Mg6Si2Ni4 cuboctahedra, edges with six equivalent Si(1)Mg6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Mg6Si2Ni4 cuboctahedra. is represented by the CIF card [CIF]
data_Mg2SiNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.639
_cell_length_b   4.639
_cell_length_c   4.639
_cell_angle_alpha   64.465
_cell_angle_beta   64.465
_cell_angle_gamma   64.465
_symmetry_Int_Tables_number   1
_cell_volume   77.518
_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
  Mg  Mg0  1  0.125  0.125  0.125  1.0
  Mg  Mg1  1  0.875  0.875  0.875  1.0
  Si  Si2  1  0.500  0.500  0.500  1.0
  Ni  Ni3  1  0.500  0.500  0.000  1.0
  Ni  Ni4  1  0.500  0.000  0.500  1.0
  Ni  Ni5  1  0.000  0.500  0.500  1.0
[/CIF]
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