The material described by EuNi9Si2 crystallizes in the tetragonal I4_1/amd space group. Eu(1) is bonded in a 18-coordinate geometry to two equivalent Ni(1) and sixteen equivalent Ni(2) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 14-coordinate geometry to two equivalent Eu(1), eight equivalent Ni(2), and four equivalent Si(1) atoms. In the second Ni site, Ni(2) is bonded to two equivalent Eu(1), one Ni(1), seven equivalent Ni(2), and two equivalent Si(1) atoms to form a mixture of distorted face, corner, and edge-sharing NiEu2Si2Ni8 cuboctahedra. Si(1) is bonded in a 10-coordinate geometry to two equivalent Ni(1) and eight equivalent Ni(2) atoms. is represented by the CIF file [CIF]
data_EuSi2Ni9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.593
_cell_length_b   7.593
_cell_length_c   7.593
_cell_angle_alpha   99.605
_cell_angle_beta   99.605
_cell_angle_gamma   131.782
_symmetry_Int_Tables_number   1
_cell_volume   297.960
_cell_formula_units_Z   2
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
  Eu  Eu0  1  0.500  0.500  0.000  1.0
  Eu  Eu1  1  0.750  0.250  0.500  1.0
  Si  Si2  1  0.625  0.875  0.750  1.0
  Si  Si3  1  0.125  0.375  0.250  1.0
  Si  Si4  1  0.125  0.875  0.750  1.0
  Si  Si5  1  0.125  0.875  0.250  1.0
  Ni  Ni6  1  0.250  0.750  0.500  1.0
  Ni  Ni7  1  0.000  0.000  0.000  1.0
  Ni  Ni8  1  0.688  0.016  0.080  1.0
  Ni  Ni9  1  0.688  0.608  0.672  1.0
  Ni  Ni10  1  0.266  0.438  0.580  1.0
  Ni  Ni11  1  0.266  0.687  0.828  1.0
  Ni  Ni12  1  0.937  0.016  0.328  1.0
  Ni  Ni13  1  0.937  0.608  0.920  1.0
  Ni  Ni14  1  0.858  0.438  0.172  1.0
  Ni  Ni15  1  0.858  0.687  0.420  1.0
  Ni  Ni16  1  0.562  0.734  0.420  1.0
  Ni  Ni17  1  0.562  0.142  0.828  1.0
  Ni  Ni18  1  0.984  0.312  0.920  1.0
  Ni  Ni19  1  0.984  0.063  0.672  1.0
  Ni  Ni20  1  0.313  0.734  0.172  1.0
  Ni  Ni21  1  0.313  0.142  0.580  1.0
  Ni  Ni22  1  0.392  0.312  0.328  1.0
  Ni  Ni23  1  0.392  0.063  0.080  1.0
[/CIF]
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The material described by EuNi9Si2 crystallizes in the tetragonal I4_1/amd space group. Eu(1) is bonded in a 18-coordinate geometry to two equivalent Ni(1) and sixteen equivalent Ni(2) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 14-coordinate geometry to two equivalent Eu(1), eight equivalent Ni(2), and four equivalent Si(1) atoms. In the second Ni site, Ni(2) is bonded to two equivalent Eu(1), one Ni(1), seven equivalent Ni(2), and two equivalent Si(1) atoms to form a mixture of distorted face, corner, and edge-sharing NiEu2Si2Ni8 cuboctahedra. Si(1) is bonded in a 10-coordinate geometry to two equivalent Ni(1) and eight equivalent Ni(2) atoms. is represented by the CIF file [CIF]
data_EuSi2Ni9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.593
_cell_length_b   7.593
_cell_length_c   7.593
_cell_angle_alpha   99.605
_cell_angle_beta   99.605
_cell_angle_gamma   131.782
_symmetry_Int_Tables_number   1
_cell_volume   297.960
_cell_formula_units_Z   2
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
  Eu  Eu0  1  0.500  0.500  0.000  1.0
  Eu  Eu1  1  0.750  0.250  0.500  1.0
  Si  Si2  1  0.625  0.875  0.750  1.0
  Si  Si3  1  0.125  0.375  0.250  1.0
  Si  Si4  1  0.125  0.875  0.750  1.0
  Si  Si5  1  0.125  0.875  0.250  1.0
  Ni  Ni6  1  0.250  0.750  0.500  1.0
  Ni  Ni7  1  0.000  0.000  0.000  1.0
  Ni  Ni8  1  0.688  0.016  0.080  1.0
  Ni  Ni9  1  0.688  0.608  0.672  1.0
  Ni  Ni10  1  0.266  0.438  0.580  1.0
  Ni  Ni11  1  0.266  0.687  0.828  1.0
  Ni  Ni12  1  0.937  0.016  0.328  1.0
  Ni  Ni13  1  0.937  0.608  0.920  1.0
  Ni  Ni14  1  0.858  0.438  0.172  1.0
  Ni  Ni15  1  0.858  0.687  0.420  1.0
  Ni  Ni16  1  0.562  0.734  0.420  1.0
  Ni  Ni17  1  0.562  0.142  0.828  1.0
  Ni  Ni18  1  0.984  0.312  0.920  1.0
  Ni  Ni19  1  0.984  0.063  0.672  1.0
  Ni  Ni20  1  0.313  0.734  0.172  1.0
  Ni  Ni21  1  0.313  0.142  0.580  1.0
  Ni  Ni22  1  0.392  0.312  0.328  1.0
  Ni  Ni23  1  0.392  0.063  0.080  1.0
[/CIF]
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