The crystal structure described by Nb4Ni4Si7 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 7-coordinate geometry to four equivalent Ni(1), two equivalent Si(2), two equivalent Si(4), and three equivalent Si(3) atoms. In the second Nb site, Nb(2) is bonded in a 7-coordinate geometry to four equivalent Ni(1), one Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. Ni(1) is bonded to two equivalent Nb(1), two equivalent Nb(2), two equivalent Ni(1), two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms to form a mixture of distorted edge, face, and corner-sharing NiNb4Si6Ni2 cuboctahedra. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 6-coordinate geometry to one Nb(2), four equivalent Ni(1), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to four equivalent Nb(1), four equivalent Nb(2), and two equivalent Si(2) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Nb(2), three equivalent Nb(1), and four equivalent Ni(1) atoms. In the fourth Si site, Si(4) is bonded in a 8-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), and four equivalent Ni(1) atoms. is represented by the CIF card [CIF]
data_Nb4Si7Ni4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.290
_cell_length_b   9.290
_cell_length_c   9.290
_cell_angle_alpha   94.192
_cell_angle_beta   94.192
_cell_angle_gamma   148.629
_symmetry_Int_Tables_number   1
_cell_volume   401.894
_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
  Nb  Nb0  1  0.135  0.135  0.269  1.0
  Nb  Nb1  1  0.865  0.865  0.731  1.0
  Nb  Nb2  1  0.865  0.135  0.000  1.0
  Nb  Nb3  1  0.135  0.865  0.000  1.0
  Nb  Nb4  1  0.500  0.309  0.809  1.0
  Nb  Nb5  1  0.500  0.691  0.191  1.0
  Nb  Nb6  1  0.691  0.500  0.191  1.0
  Nb  Nb7  1  0.309  0.500  0.809  1.0
  Si  Si8  1  0.500  0.093  0.593  1.0
  Si  Si9  1  0.500  0.907  0.407  1.0
  Si  Si10  1  0.907  0.500  0.407  1.0
  Si  Si11  1  0.093  0.500  0.593  1.0
  Si  Si12  1  0.751  0.751  0.000  1.0
  Si  Si13  1  0.249  0.249  0.000  1.0
  Si  Si14  1  0.292  0.292  0.585  1.0
  Si  Si15  1  0.708  0.708  0.415  1.0
  Si  Si16  1  0.708  0.292  0.000  1.0
  Si  Si17  1  0.292  0.708  0.000  1.0
  Si  Si18  1  0.000  0.292  0.292  1.0
  Si  Si19  1  0.000  0.708  0.708  1.0
  Si  Si20  1  0.708  0.000  0.708  1.0
  Si  Si21  1  0.292  0.000  0.292  1.0
  Ni  Ni22  1  0.398  0.898  0.796  1.0
  Ni  Ni23  1  0.102  0.602  0.204  1.0
  Ni  Ni24  1  0.102  0.898  0.500  1.0
  Ni  Ni25  1  0.398  0.602  0.500  1.0
  Ni  Ni26  1  0.602  0.398  0.500  1.0
  Ni  Ni27  1  0.898  0.102  0.500  1.0
  Ni  Ni28  1  0.898  0.398  0.796  1.0
  Ni  Ni29  1  0.602  0.102  0.204  1.0
[/CIF]
.
The crystal structure described by Nb4Ni4Si7 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 7-coordinate geometry to four equivalent Ni(1), two equivalent Si(2), two equivalent Si(4), and three equivalent Si(3) atoms. In the second Nb site, Nb(2) is bonded in a 7-coordinate geometry to four equivalent Ni(1), one Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. Ni(1) is bonded to two equivalent Nb(1), two equivalent Nb(2), two equivalent Ni(1), two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms to form a mixture of distorted edge, face, and corner-sharing NiNb4Si6Ni2 cuboctahedra. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 6-coordinate geometry to one Nb(2), four equivalent Ni(1), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 10-coordinate geometry to four equivalent Nb(1), four equivalent Nb(2), and two equivalent Si(2) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Nb(2), three equivalent Nb(1), and four equivalent Ni(1) atoms. In the fourth Si site, Si(4) is bonded in a 8-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), and four equivalent Ni(1) atoms. is represented by the CIF card [CIF]
data_Nb4Si7Ni4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.290
_cell_length_b   9.290
_cell_length_c   9.290
_cell_angle_alpha   94.192
_cell_angle_beta   94.192
_cell_angle_gamma   148.629
_symmetry_Int_Tables_number   1
_cell_volume   401.894
_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
  Nb  Nb0  1  0.135  0.135  0.269  1.0
  Nb  Nb1  1  0.865  0.865  0.731  1.0
  Nb  Nb2  1  0.865  0.135  0.000  1.0
  Nb  Nb3  1  0.135  0.865  0.000  1.0
  Nb  Nb4  1  0.500  0.309  0.809  1.0
  Nb  Nb5  1  0.500  0.691  0.191  1.0
  Nb  Nb6  1  0.691  0.500  0.191  1.0
  Nb  Nb7  1  0.309  0.500  0.809  1.0
  Si  Si8  1  0.500  0.093  0.593  1.0
  Si  Si9  1  0.500  0.907  0.407  1.0
  Si  Si10  1  0.907  0.500  0.407  1.0
  Si  Si11  1  0.093  0.500  0.593  1.0
  Si  Si12  1  0.751  0.751  0.000  1.0
  Si  Si13  1  0.249  0.249  0.000  1.0
  Si  Si14  1  0.292  0.292  0.585  1.0
  Si  Si15  1  0.708  0.708  0.415  1.0
  Si  Si16  1  0.708  0.292  0.000  1.0
  Si  Si17  1  0.292  0.708  0.000  1.0
  Si  Si18  1  0.000  0.292  0.292  1.0
  Si  Si19  1  0.000  0.708  0.708  1.0
  Si  Si20  1  0.708  0.000  0.708  1.0
  Si  Si21  1  0.292  0.000  0.292  1.0
  Ni  Ni22  1  0.398  0.898  0.796  1.0
  Ni  Ni23  1  0.102  0.602  0.204  1.0
  Ni  Ni24  1  0.102  0.898  0.500  1.0
  Ni  Ni25  1  0.398  0.602  0.500  1.0
  Ni  Ni26  1  0.602  0.398  0.500  1.0
  Ni  Ni27  1  0.898  0.102  0.500  1.0
  Ni  Ni28  1  0.898  0.398  0.796  1.0
  Ni  Ni29  1  0.602  0.102  0.204  1.0
[/CIF]
.