The material described by Nb6Cr7 is Frank-Kasper $\mu$ Phase structured and crystallizes in the trigonal R-3m space group. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 15-coordinate geometry to three equivalent Nb(1), six equivalent Nb(3), and six equivalent Cr(2) atoms. In the second Nb site, Nb(2) is bonded in a 16-coordinate geometry to one Nb(3), three equivalent Nb(2), three equivalent Cr(1), and nine equivalent Cr(2) atoms. In the third Nb site, Nb(3) is bonded in a 14-coordinate geometry to one Nb(2), one Nb(3), six equivalent Nb(1), and six equivalent Cr(2) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to six equivalent Nb(2) and six equivalent Cr(2) atoms to form CrNb6Cr6 cuboctahedra that share corners with twelve equivalent Cr(2)Nb7Cr5 cuboctahedra, edges with six equivalent Cr(1)Nb6Cr6 cuboctahedra, and faces with eighteen equivalent Cr(2)Nb7Cr5 cuboctahedra. In the second Cr site, Cr(2) is bonded to two equivalent Nb(1), two equivalent Nb(3), three equivalent Nb(2), one Cr(1), and four equivalent Cr(2) atoms to form CrNb7Cr5 cuboctahedra that share corners with two equivalent Cr(1)Nb6Cr6 cuboctahedra, corners with thirteen equivalent Cr(2)Nb7Cr5 cuboctahedra, edges with five equivalent Cr(2)Nb7Cr5 cuboctahedra, faces with three equivalent Cr(1)Nb6Cr6 cuboctahedra, and faces with ten equivalent Cr(2)Nb7Cr5 cuboctahedra. is represented by the CIF card [CIF]
data_Nb6Cr7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.917
_cell_length_b   4.917
_cell_length_c   9.672
_cell_angle_alpha   75.274
_cell_angle_beta   75.274
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   193.579
_cell_formula_units_Z   1
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  0.833  0.833  0.502  1.0
  Nb  Nb1  1  0.167  0.167  0.498  1.0
  Nb  Nb2  1  0.649  0.649  0.052  1.0
  Nb  Nb3  1  0.351  0.351  0.948  1.0
  Nb  Nb4  1  0.547  0.547  0.358  1.0
  Nb  Nb5  1  0.453  0.453  0.642  1.0
  Cr  Cr6  1  0.000  0.000  0.000  1.0
  Cr  Cr7  1  0.905  0.410  0.780  1.0
  Cr  Cr8  1  0.410  0.905  0.780  1.0
  Cr  Cr9  1  0.905  0.905  0.780  1.0
  Cr  Cr10  1  0.095  0.590  0.220  1.0
  Cr  Cr11  1  0.590  0.095  0.220  1.0
  Cr  Cr12  1  0.095  0.095  0.220  1.0
[/CIF]
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The material described by Nb6Cr7 is Frank-Kasper $\mu$ Phase structured and crystallizes in the trigonal R-3m space group. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 15-coordinate geometry to three equivalent Nb(1), six equivalent Nb(3), and six equivalent Cr(2) atoms. In the second Nb site, Nb(2) is bonded in a 16-coordinate geometry to one Nb(3), three equivalent Nb(2), three equivalent Cr(1), and nine equivalent Cr(2) atoms. In the third Nb site, Nb(3) is bonded in a 14-coordinate geometry to one Nb(2), one Nb(3), six equivalent Nb(1), and six equivalent Cr(2) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to six equivalent Nb(2) and six equivalent Cr(2) atoms to form CrNb6Cr6 cuboctahedra that share corners with twelve equivalent Cr(2)Nb7Cr5 cuboctahedra, edges with six equivalent Cr(1)Nb6Cr6 cuboctahedra, and faces with eighteen equivalent Cr(2)Nb7Cr5 cuboctahedra. In the second Cr site, Cr(2) is bonded to two equivalent Nb(1), two equivalent Nb(3), three equivalent Nb(2), one Cr(1), and four equivalent Cr(2) atoms to form CrNb7Cr5 cuboctahedra that share corners with two equivalent Cr(1)Nb6Cr6 cuboctahedra, corners with thirteen equivalent Cr(2)Nb7Cr5 cuboctahedra, edges with five equivalent Cr(2)Nb7Cr5 cuboctahedra, faces with three equivalent Cr(1)Nb6Cr6 cuboctahedra, and faces with ten equivalent Cr(2)Nb7Cr5 cuboctahedra. is represented by the CIF card [CIF]
data_Nb6Cr7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.917
_cell_length_b   4.917
_cell_length_c   9.672
_cell_angle_alpha   75.274
_cell_angle_beta   75.274
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   193.579
_cell_formula_units_Z   1
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  0.833  0.833  0.502  1.0
  Nb  Nb1  1  0.167  0.167  0.498  1.0
  Nb  Nb2  1  0.649  0.649  0.052  1.0
  Nb  Nb3  1  0.351  0.351  0.948  1.0
  Nb  Nb4  1  0.547  0.547  0.358  1.0
  Nb  Nb5  1  0.453  0.453  0.642  1.0
  Cr  Cr6  1  0.000  0.000  0.000  1.0
  Cr  Cr7  1  0.905  0.410  0.780  1.0
  Cr  Cr8  1  0.410  0.905  0.780  1.0
  Cr  Cr9  1  0.905  0.905  0.780  1.0
  Cr  Cr10  1  0.095  0.590  0.220  1.0
  Cr  Cr11  1  0.590  0.095  0.220  1.0
  Cr  Cr12  1  0.095  0.095  0.220  1.0
[/CIF]
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