The material structure described by Cr2Nb is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the tetragonal I-4m2 space group. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 14-coordinate geometry to four equivalent Nb(2), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), and four equivalent Cr(4) atoms. In the second Nb site, Nb(2) is bonded in a 14-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), two equivalent Nb(3), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), and two equivalent Cr(4) atoms. In the third Nb site, Nb(3) is bonded in a 14-coordinate geometry to four equivalent Nb(2), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), and four equivalent Cr(4) atoms. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one Nb(1), one Nb(3), two equivalent Nb(2), two equivalent Cr(4), three equivalent Cr(2), and three equivalent Cr(3) atoms to form a mixture of distorted corner and face-sharing CrNb4Cr8 cuboctahedra. In the second Cr site, Cr(2) is bonded in a 12-coordinate geometry to one Nb(1), one Nb(3), two equivalent Nb(2), two equivalent Cr(4), three equivalent Cr(1), and three equivalent Cr(2) atoms. In the third Cr site, Cr(3) is bonded to one Nb(1), one Nb(3), two equivalent Nb(2), two equivalent Cr(4), three equivalent Cr(1), and three equivalent Cr(3) atoms to form a mixture of corner and face-sharing CrNb4Cr8 cuboctahedra. In the fourth Cr site, Cr(4) is bonded in a 12-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), two equivalent Nb(3), two equivalent Cr(1), two equivalent Cr(2), and two equivalent Cr(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_NbCr2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.820
_cell_length_b   7.820
_cell_length_c   7.820
_cell_angle_alpha   118.367
_cell_angle_beta   118.367
_cell_angle_gamma   92.852
_symmetry_Int_Tables_number   1
_cell_volume   346.011
_cell_formula_units_Z   8
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  0.341  0.341  0.000  1.0
  Nb  Nb1  1  0.659  0.659  0.000  1.0
  Nb  Nb2  1  0.553  0.053  0.106  1.0
  Nb  Nb3  1  0.947  0.447  0.894  1.0
  Nb  Nb4  1  0.947  0.053  0.500  1.0
  Nb  Nb5  1  0.553  0.447  0.500  1.0
  Nb  Nb6  1  0.940  0.440  0.500  1.0
  Nb  Nb7  1  0.560  0.060  0.500  1.0
  Cr  Cr8  1  0.128  0.377  0.249  1.0
  Cr  Cr9  1  0.121  0.872  0.249  1.0
  Cr  Cr10  1  0.623  0.872  0.751  1.0
  Cr  Cr11  1  0.128  0.879  0.751  1.0
  Cr  Cr12  1  0.915  0.757  0.841  1.0
  Cr  Cr13  1  0.926  0.085  0.841  1.0
  Cr  Cr14  1  0.243  0.085  0.159  1.0
  Cr  Cr15  1  0.915  0.074  0.159  1.0
  Cr  Cr16  1  0.340  0.003  0.663  1.0
  Cr  Cr17  1  0.323  0.660  0.663  1.0
  Cr  Cr18  1  0.997  0.660  0.337  1.0
  Cr  Cr19  1  0.340  0.677  0.337  1.0
  Cr  Cr20  1  0.706  0.706  0.412  1.0
  Cr  Cr21  1  0.294  0.294  0.588  1.0
  Cr  Cr22  1  0.294  0.706  0.000  1.0
  Cr  Cr23  1  0.706  0.294  0.000  1.0
[/CIF]
.
The material structure described by Cr2Nb is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the tetragonal I-4m2 space group. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 14-coordinate geometry to four equivalent Nb(2), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), and four equivalent Cr(4) atoms. In the second Nb site, Nb(2) is bonded in a 14-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), two equivalent Nb(3), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), and two equivalent Cr(4) atoms. In the third Nb site, Nb(3) is bonded in a 14-coordinate geometry to four equivalent Nb(2), two equivalent Cr(1), two equivalent Cr(2), two equivalent Cr(3), and four equivalent Cr(4) atoms. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one Nb(1), one Nb(3), two equivalent Nb(2), two equivalent Cr(4), three equivalent Cr(2), and three equivalent Cr(3) atoms to form a mixture of distorted corner and face-sharing CrNb4Cr8 cuboctahedra. In the second Cr site, Cr(2) is bonded in a 12-coordinate geometry to one Nb(1), one Nb(3), two equivalent Nb(2), two equivalent Cr(4), three equivalent Cr(1), and three equivalent Cr(2) atoms. In the third Cr site, Cr(3) is bonded to one Nb(1), one Nb(3), two equivalent Nb(2), two equivalent Cr(4), three equivalent Cr(1), and three equivalent Cr(3) atoms to form a mixture of corner and face-sharing CrNb4Cr8 cuboctahedra. In the fourth Cr site, Cr(4) is bonded in a 12-coordinate geometry to two equivalent Nb(1), two equivalent Nb(2), two equivalent Nb(3), two equivalent Cr(1), two equivalent Cr(2), and two equivalent Cr(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_NbCr2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.820
_cell_length_b   7.820
_cell_length_c   7.820
_cell_angle_alpha   118.367
_cell_angle_beta   118.367
_cell_angle_gamma   92.852
_symmetry_Int_Tables_number   1
_cell_volume   346.011
_cell_formula_units_Z   8
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  0.341  0.341  0.000  1.0
  Nb  Nb1  1  0.659  0.659  0.000  1.0
  Nb  Nb2  1  0.553  0.053  0.106  1.0
  Nb  Nb3  1  0.947  0.447  0.894  1.0
  Nb  Nb4  1  0.947  0.053  0.500  1.0
  Nb  Nb5  1  0.553  0.447  0.500  1.0
  Nb  Nb6  1  0.940  0.440  0.500  1.0
  Nb  Nb7  1  0.560  0.060  0.500  1.0
  Cr  Cr8  1  0.128  0.377  0.249  1.0
  Cr  Cr9  1  0.121  0.872  0.249  1.0
  Cr  Cr10  1  0.623  0.872  0.751  1.0
  Cr  Cr11  1  0.128  0.879  0.751  1.0
  Cr  Cr12  1  0.915  0.757  0.841  1.0
  Cr  Cr13  1  0.926  0.085  0.841  1.0
  Cr  Cr14  1  0.243  0.085  0.159  1.0
  Cr  Cr15  1  0.915  0.074  0.159  1.0
  Cr  Cr16  1  0.340  0.003  0.663  1.0
  Cr  Cr17  1  0.323  0.660  0.663  1.0
  Cr  Cr18  1  0.997  0.660  0.337  1.0
  Cr  Cr19  1  0.340  0.677  0.337  1.0
  Cr  Cr20  1  0.706  0.706  0.412  1.0
  Cr  Cr21  1  0.294  0.294  0.588  1.0
  Cr  Cr22  1  0.294  0.706  0.000  1.0
  Cr  Cr23  1  0.706  0.294  0.000  1.0
[/CIF]
.