The material structure described by YCo9Si4 crystallizes in the tetragonal I4/mcm space group. Y(1) is bonded in a 24-coordinate geometry to eight equivalent Co(1), eight equivalent Co(2), and eight equivalent Si(1) atoms. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent Y(1), one Co(3), two equivalent Co(2), three equivalent Co(1), and four equivalent Si(1) atoms to form distorted CoY2Co6Si4 cuboctahedra that share  a cornercorner with one Co(3)Co8Si4 cuboctahedra, corners with eleven equivalent Co(1)Y2Co6Si4 cuboctahedra, faces with two equivalent Co(3)Co8Si4 cuboctahedra, and faces with seven equivalent Co(1)Y2Co6Si4 cuboctahedra. In the second Co site, Co(2) is bonded in a 11-coordinate geometry to two equivalent Y(1), one Co(3), two equivalent Co(1), two equivalent Co(2), and four equivalent Si(1) atoms. In the third Co site, Co(3) is bonded to four equivalent Co(1), four equivalent Co(2), and four equivalent Si(1) atoms to form a mixture of corner and face-sharing CoCo8Si4 cuboctahedra. Si(1) is bonded in a 11-coordinate geometry to two equivalent Y(1), one Co(3), four equivalent Co(1), and four equivalent Co(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_YCo9Si4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.909
_cell_length_b   7.909
_cell_length_c   7.909
_cell_angle_alpha   121.579
_cell_angle_beta   121.579
_cell_angle_gamma   87.286
_symmetry_Int_Tables_number   1
_cell_volume   340.998
_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
  Y  Y0  1  0.750  0.750  0.000  1.0
  Y  Y1  1  0.250  0.250  0.000  1.0
  Co  Co2  1  0.069  0.198  0.268  1.0
  Co  Co3  1  0.931  0.802  0.732  1.0
  Co  Co4  1  0.569  0.302  0.871  1.0
  Co  Co5  1  0.431  0.698  0.129  1.0
  Co  Co6  1  0.802  0.069  0.871  1.0
  Co  Co7  1  0.198  0.931  0.129  1.0
  Co  Co8  1  0.698  0.569  0.268  1.0
  Co  Co9  1  0.302  0.431  0.732  1.0
  Co  Co10  1  0.450  0.950  0.761  1.0
  Co  Co11  1  0.189  0.689  0.239  1.0
  Co  Co12  1  0.950  0.189  0.500  1.0
  Co  Co13  1  0.689  0.450  0.500  1.0
  Co  Co14  1  0.550  0.050  0.239  1.0
  Co  Co15  1  0.811  0.311  0.761  1.0
  Co  Co16  1  0.050  0.811  0.500  1.0
  Co  Co17  1  0.311  0.550  0.500  1.0
  Co  Co18  1  0.000  0.500  0.500  1.0
  Co  Co19  1  0.500  0.000  0.500  1.0
  Si  Si20  1  0.046  0.546  0.838  1.0
  Si  Si21  1  0.708  0.208  0.162  1.0
  Si  Si22  1  0.546  0.708  0.500  1.0
  Si  Si23  1  0.208  0.046  0.500  1.0
  Si  Si24  1  0.954  0.454  0.162  1.0
  Si  Si25  1  0.292  0.792  0.838  1.0
  Si  Si26  1  0.454  0.292  0.500  1.0
  Si  Si27  1  0.792  0.954  0.500  1.0
[/CIF]
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The material structure described by YCo9Si4 crystallizes in the tetragonal I4/mcm space group. Y(1) is bonded in a 24-coordinate geometry to eight equivalent Co(1), eight equivalent Co(2), and eight equivalent Si(1) atoms. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent Y(1), one Co(3), two equivalent Co(2), three equivalent Co(1), and four equivalent Si(1) atoms to form distorted CoY2Co6Si4 cuboctahedra that share  a cornercorner with one Co(3)Co8Si4 cuboctahedra, corners with eleven equivalent Co(1)Y2Co6Si4 cuboctahedra, faces with two equivalent Co(3)Co8Si4 cuboctahedra, and faces with seven equivalent Co(1)Y2Co6Si4 cuboctahedra. In the second Co site, Co(2) is bonded in a 11-coordinate geometry to two equivalent Y(1), one Co(3), two equivalent Co(1), two equivalent Co(2), and four equivalent Si(1) atoms. In the third Co site, Co(3) is bonded to four equivalent Co(1), four equivalent Co(2), and four equivalent Si(1) atoms to form a mixture of corner and face-sharing CoCo8Si4 cuboctahedra. Si(1) is bonded in a 11-coordinate geometry to two equivalent Y(1), one Co(3), four equivalent Co(1), and four equivalent Co(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_YCo9Si4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.909
_cell_length_b   7.909
_cell_length_c   7.909
_cell_angle_alpha   121.579
_cell_angle_beta   121.579
_cell_angle_gamma   87.286
_symmetry_Int_Tables_number   1
_cell_volume   340.998
_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
  Y  Y0  1  0.750  0.750  0.000  1.0
  Y  Y1  1  0.250  0.250  0.000  1.0
  Co  Co2  1  0.069  0.198  0.268  1.0
  Co  Co3  1  0.931  0.802  0.732  1.0
  Co  Co4  1  0.569  0.302  0.871  1.0
  Co  Co5  1  0.431  0.698  0.129  1.0
  Co  Co6  1  0.802  0.069  0.871  1.0
  Co  Co7  1  0.198  0.931  0.129  1.0
  Co  Co8  1  0.698  0.569  0.268  1.0
  Co  Co9  1  0.302  0.431  0.732  1.0
  Co  Co10  1  0.450  0.950  0.761  1.0
  Co  Co11  1  0.189  0.689  0.239  1.0
  Co  Co12  1  0.950  0.189  0.500  1.0
  Co  Co13  1  0.689  0.450  0.500  1.0
  Co  Co14  1  0.550  0.050  0.239  1.0
  Co  Co15  1  0.811  0.311  0.761  1.0
  Co  Co16  1  0.050  0.811  0.500  1.0
  Co  Co17  1  0.311  0.550  0.500  1.0
  Co  Co18  1  0.000  0.500  0.500  1.0
  Co  Co19  1  0.500  0.000  0.500  1.0
  Si  Si20  1  0.046  0.546  0.838  1.0
  Si  Si21  1  0.708  0.208  0.162  1.0
  Si  Si22  1  0.546  0.708  0.500  1.0
  Si  Si23  1  0.208  0.046  0.500  1.0
  Si  Si24  1  0.954  0.454  0.162  1.0
  Si  Si25  1  0.292  0.792  0.838  1.0
  Si  Si26  1  0.454  0.292  0.500  1.0
  Si  Si27  1  0.792  0.954  0.500  1.0
[/CIF]
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