The crystal structure described by Si(Ni3Se)2 crystallizes in the tetragonal I4mm space group. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Ni(2), four equivalent Ni(3), and four equivalent Si(1) atoms to form NiSi4Ni8 cuboctahedra that share corners with four equivalent Ni(1)Si4Ni8 cuboctahedra, faces with four equivalent Ni(1)Si4Ni8 cuboctahedra, and faces with four equivalent Si(1)Ni12 cuboctahedra. In the second Ni site, Ni(2) is bonded in a distorted water-like geometry to two equivalent Ni(1), two equivalent Si(1), and two equivalent Se(1) atoms. In the third Ni site, Ni(3) is bonded in a 2-coordinate geometry to two equivalent Ni(1), two equivalent Si(1), and two equivalent Se(2) atoms. In the fourth Ni site, Ni(4) is bonded to one Se(1) and four equivalent Se(2) atoms to form a mixture of distorted corner and edge-sharing NiSe5 square pyramids. Si(1) is bonded to four equivalent Ni(1), four equivalent Ni(2), and four equivalent Ni(3) atoms to form SiNi12 cuboctahedra that share corners with four equivalent Si(1)Ni12 cuboctahedra, faces with four equivalent Ni(1)Si4Ni8 cuboctahedra, and faces with four equivalent Si(1)Ni12 cuboctahedra. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to one Ni(4) and four equivalent Ni(2) atoms. In the second Se site, Se(2) is bonded in a 8-coordinate geometry to four equivalent Ni(3) and four equivalent Ni(4) atoms. is represented by the CIF file [CIF]
data_Si(Ni3Se)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.579
_cell_length_b   3.579
_cell_length_c   9.512
_cell_angle_alpha   79.157
_cell_angle_beta   79.157
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   117.440
_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  1.000  1.0
  Ni  Ni1  1  0.499  0.499  0.002  1.0
  Ni  Ni2  1  0.906  0.406  0.187  1.0
  Ni  Ni3  1  0.406  0.906  0.187  1.0
  Ni  Ni4  1  0.091  0.591  0.818  1.0
  Ni  Ni5  1  0.591  0.091  0.818  1.0
  Ni  Ni6  1  0.199  0.199  0.602  1.0
  Se  Se7  1  0.324  0.324  0.351  1.0
  Se  Se8  1  0.682  0.682  0.637  1.0
[/CIF]
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The crystal structure described by Si(Ni3Se)2 crystallizes in the tetragonal I4mm space group. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Ni(2), four equivalent Ni(3), and four equivalent Si(1) atoms to form NiSi4Ni8 cuboctahedra that share corners with four equivalent Ni(1)Si4Ni8 cuboctahedra, faces with four equivalent Ni(1)Si4Ni8 cuboctahedra, and faces with four equivalent Si(1)Ni12 cuboctahedra. In the second Ni site, Ni(2) is bonded in a distorted water-like geometry to two equivalent Ni(1), two equivalent Si(1), and two equivalent Se(1) atoms. In the third Ni site, Ni(3) is bonded in a 2-coordinate geometry to two equivalent Ni(1), two equivalent Si(1), and two equivalent Se(2) atoms. In the fourth Ni site, Ni(4) is bonded to one Se(1) and four equivalent Se(2) atoms to form a mixture of distorted corner and edge-sharing NiSe5 square pyramids. Si(1) is bonded to four equivalent Ni(1), four equivalent Ni(2), and four equivalent Ni(3) atoms to form SiNi12 cuboctahedra that share corners with four equivalent Si(1)Ni12 cuboctahedra, faces with four equivalent Ni(1)Si4Ni8 cuboctahedra, and faces with four equivalent Si(1)Ni12 cuboctahedra. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to one Ni(4) and four equivalent Ni(2) atoms. In the second Se site, Se(2) is bonded in a 8-coordinate geometry to four equivalent Ni(3) and four equivalent Ni(4) atoms. is represented by the CIF file [CIF]
data_Si(Ni3Se)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.579
_cell_length_b   3.579
_cell_length_c   9.512
_cell_angle_alpha   79.157
_cell_angle_beta   79.157
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   117.440
_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  1.000  1.0
  Ni  Ni1  1  0.499  0.499  0.002  1.0
  Ni  Ni2  1  0.906  0.406  0.187  1.0
  Ni  Ni3  1  0.406  0.906  0.187  1.0
  Ni  Ni4  1  0.091  0.591  0.818  1.0
  Ni  Ni5  1  0.591  0.091  0.818  1.0
  Ni  Ni6  1  0.199  0.199  0.602  1.0
  Se  Se7  1  0.324  0.324  0.351  1.0
  Se  Se8  1  0.682  0.682  0.637  1.0
[/CIF]
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