The compound described by NbFeSi2 crystallizes in the orthorhombic Pbam space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 8-coordinate geometry to one Si(4), one Si(5), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. In the second Nb site, Nb(2) is bonded in a 7-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and three equivalent Si(5) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one Si(2), one Si(3), one Si(4), one Si(5), and two equivalent Si(1) atoms. In the second Fe site, Fe(2) is bonded to two equivalent Si(1), two equivalent Si(4), and two equivalent Si(5) atoms to form distorted edge-sharing FeSi6 cuboctahedra. There are five inequivalent Si sites. In the first Si site, Si(2) is bonded in a 7-coordinate geometry to four equivalent Nb(1), two equivalent Fe(1), and one Si(2) atom. In the second Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Nb(2), four equivalent Nb(1), two equivalent Fe(1), and one Si(3) atom. In the third Si site, Si(4) is bonded in a 6-coordinate geometry to two equivalent Nb(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the fourth Si site, Si(5) is bonded in a 9-coordinate geometry to two equivalent Nb(1), three equivalent Nb(2), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the fifth Si site, Si(1) is bonded in a 7-coordinate geometry to one Nb(2), two equivalent Nb(1), one Fe(2), two equivalent Fe(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_NbFeSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.568
_cell_length_b   8.696
_cell_length_c   9.684
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   637.299
_cell_formula_units_Z   12
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  0.244  0.828  0.451  1.0
  Nb  Nb1  1  0.244  0.172  0.549  1.0
  Nb  Nb2  1  0.756  0.328  0.049  1.0
  Nb  Nb3  1  0.756  0.672  0.951  1.0
  Nb  Nb4  1  0.756  0.172  0.549  1.0
  Nb  Nb5  1  0.756  0.828  0.451  1.0
  Nb  Nb6  1  0.244  0.672  0.951  1.0
  Nb  Nb7  1  0.244  0.328  0.049  1.0
  Nb  Nb8  1  0.000  0.831  0.182  1.0
  Nb  Nb9  1  0.000  0.169  0.818  1.0
  Nb  Nb10  1  0.000  0.331  0.318  1.0
  Nb  Nb11  1  0.000  0.669  0.682  1.0
  Fe  Fe12  1  0.250  0.590  0.246  1.0
  Fe  Fe13  1  0.250  0.410  0.754  1.0
  Fe  Fe14  1  0.750  0.090  0.254  1.0
  Fe  Fe15  1  0.750  0.910  0.746  1.0
  Fe  Fe16  1  0.750  0.410  0.754  1.0
  Fe  Fe17  1  0.750  0.590  0.246  1.0
  Fe  Fe18  1  0.250  0.910  0.746  1.0
  Fe  Fe19  1  0.250  0.090  0.254  1.0
  Fe  Fe20  1  0.245  0.500  0.500  1.0
  Fe  Fe21  1  0.755  0.000  0.000  1.0
  Fe  Fe22  1  0.755  0.500  0.500  1.0
  Fe  Fe23  1  0.245  0.000  0.000  1.0
  Si  Si24  1  0.345  0.838  0.180  1.0
  Si  Si25  1  0.345  0.162  0.820  1.0
  Si  Si26  1  0.655  0.338  0.320  1.0
  Si  Si27  1  0.655  0.662  0.680  1.0
  Si  Si28  1  0.655  0.162  0.820  1.0
  Si  Si29  1  0.655  0.838  0.180  1.0
  Si  Si30  1  0.345  0.662  0.680  1.0
  Si  Si31  1  0.345  0.338  0.320  1.0
  Si  Si32  1  0.500  0.541  0.122  1.0
  Si  Si33  1  0.500  0.459  0.878  1.0
  Si  Si34  1  0.500  0.041  0.378  1.0
  Si  Si35  1  0.500  0.959  0.622  1.0
  Si  Si36  1  0.000  0.539  0.118  1.0
  Si  Si37  1  0.000  0.461  0.882  1.0
  Si  Si38  1  0.000  0.039  0.382  1.0
  Si  Si39  1  0.000  0.961  0.618  1.0
  Si  Si40  1  0.500  0.614  0.398  1.0
  Si  Si41  1  0.500  0.386  0.602  1.0
  Si  Si42  1  0.500  0.114  0.102  1.0
  Si  Si43  1  0.500  0.886  0.898  1.0
  Si  Si44  1  0.000  0.621  0.396  1.0
  Si  Si45  1  0.000  0.379  0.604  1.0
  Si  Si46  1  0.000  0.121  0.104  1.0
  Si  Si47  1  0.000  0.879  0.896  1.0
[/CIF]
.
The compound described by NbFeSi2 crystallizes in the orthorhombic Pbam space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 8-coordinate geometry to one Si(4), one Si(5), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. In the second Nb site, Nb(2) is bonded in a 7-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and three equivalent Si(5) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one Si(2), one Si(3), one Si(4), one Si(5), and two equivalent Si(1) atoms. In the second Fe site, Fe(2) is bonded to two equivalent Si(1), two equivalent Si(4), and two equivalent Si(5) atoms to form distorted edge-sharing FeSi6 cuboctahedra. There are five inequivalent Si sites. In the first Si site, Si(2) is bonded in a 7-coordinate geometry to four equivalent Nb(1), two equivalent Fe(1), and one Si(2) atom. In the second Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Nb(2), four equivalent Nb(1), two equivalent Fe(1), and one Si(3) atom. In the third Si site, Si(4) is bonded in a 6-coordinate geometry to two equivalent Nb(1), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the fourth Si site, Si(5) is bonded in a 9-coordinate geometry to two equivalent Nb(1), three equivalent Nb(2), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the fifth Si site, Si(1) is bonded in a 7-coordinate geometry to one Nb(2), two equivalent Nb(1), one Fe(2), two equivalent Fe(1), and one Si(1) atom. is represented by the CIF card [CIF]
data_NbFeSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.568
_cell_length_b   8.696
_cell_length_c   9.684
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   637.299
_cell_formula_units_Z   12
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  0.244  0.828  0.451  1.0
  Nb  Nb1  1  0.244  0.172  0.549  1.0
  Nb  Nb2  1  0.756  0.328  0.049  1.0
  Nb  Nb3  1  0.756  0.672  0.951  1.0
  Nb  Nb4  1  0.756  0.172  0.549  1.0
  Nb  Nb5  1  0.756  0.828  0.451  1.0
  Nb  Nb6  1  0.244  0.672  0.951  1.0
  Nb  Nb7  1  0.244  0.328  0.049  1.0
  Nb  Nb8  1  0.000  0.831  0.182  1.0
  Nb  Nb9  1  0.000  0.169  0.818  1.0
  Nb  Nb10  1  0.000  0.331  0.318  1.0
  Nb  Nb11  1  0.000  0.669  0.682  1.0
  Fe  Fe12  1  0.250  0.590  0.246  1.0
  Fe  Fe13  1  0.250  0.410  0.754  1.0
  Fe  Fe14  1  0.750  0.090  0.254  1.0
  Fe  Fe15  1  0.750  0.910  0.746  1.0
  Fe  Fe16  1  0.750  0.410  0.754  1.0
  Fe  Fe17  1  0.750  0.590  0.246  1.0
  Fe  Fe18  1  0.250  0.910  0.746  1.0
  Fe  Fe19  1  0.250  0.090  0.254  1.0
  Fe  Fe20  1  0.245  0.500  0.500  1.0
  Fe  Fe21  1  0.755  0.000  0.000  1.0
  Fe  Fe22  1  0.755  0.500  0.500  1.0
  Fe  Fe23  1  0.245  0.000  0.000  1.0
  Si  Si24  1  0.345  0.838  0.180  1.0
  Si  Si25  1  0.345  0.162  0.820  1.0
  Si  Si26  1  0.655  0.338  0.320  1.0
  Si  Si27  1  0.655  0.662  0.680  1.0
  Si  Si28  1  0.655  0.162  0.820  1.0
  Si  Si29  1  0.655  0.838  0.180  1.0
  Si  Si30  1  0.345  0.662  0.680  1.0
  Si  Si31  1  0.345  0.338  0.320  1.0
  Si  Si32  1  0.500  0.541  0.122  1.0
  Si  Si33  1  0.500  0.459  0.878  1.0
  Si  Si34  1  0.500  0.041  0.378  1.0
  Si  Si35  1  0.500  0.959  0.622  1.0
  Si  Si36  1  0.000  0.539  0.118  1.0
  Si  Si37  1  0.000  0.461  0.882  1.0
  Si  Si38  1  0.000  0.039  0.382  1.0
  Si  Si39  1  0.000  0.961  0.618  1.0
  Si  Si40  1  0.500  0.614  0.398  1.0
  Si  Si41  1  0.500  0.386  0.602  1.0
  Si  Si42  1  0.500  0.114  0.102  1.0
  Si  Si43  1  0.500  0.886  0.898  1.0
  Si  Si44  1  0.000  0.621  0.396  1.0
  Si  Si45  1  0.000  0.379  0.604  1.0
  Si  Si46  1  0.000  0.121  0.104  1.0
  Si  Si47  1  0.000  0.879  0.896  1.0
[/CIF]
.