The structure described by Np(CrAl2)4 crystallizes in the tetragonal I4/mmm space group. Np(1) is bonded in a 20-coordinate geometry to eight equivalent Cr(1), four equivalent Al(1), and eight equivalent Al(2) atoms. Cr(1) is bonded to two equivalent Np(1), two equivalent Cr(1), four equivalent Al(1), and four equivalent Al(2) atoms to form a mixture of distorted face, corner, and edge-sharing CrNp2Al8Cr2 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to one Np(1), four equivalent Cr(1), one Al(1), and four equivalent Al(2) atoms. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Np(1), four equivalent Cr(1), two equivalent Al(2), and four equivalent Al(1) atoms. is represented by the CIF card [CIF]
data_Np(Al2Cr)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.968
_cell_length_b   6.691
_cell_length_c   6.691
_cell_angle_alpha   97.922
_cell_angle_beta   111.792
_cell_angle_gamma   68.208
_symmetry_Int_Tables_number   1
_cell_volume   191.762
_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
  Np  Np0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.660  0.340  0.660  1.0
  Al  Al2  1  0.340  0.660  0.340  1.0
  Al  Al3  1  0.000  0.340  0.340  1.0
  Al  Al4  1  0.000  0.660  0.660  1.0
  Al  Al5  1  0.717  0.783  0.217  1.0
  Al  Al6  1  0.283  0.217  0.783  1.0
  Al  Al7  1  0.500  0.783  0.783  1.0
  Al  Al8  1  0.500  0.217  0.217  1.0
  Cr  Cr9  1  0.500  0.000  0.500  1.0
  Cr  Cr10  1  0.000  0.000  0.500  1.0
  Cr  Cr11  1  0.500  0.500  0.000  1.0
  Cr  Cr12  1  0.000  0.500  0.000  1.0
[/CIF]
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The structure described by Np(CrAl2)4 crystallizes in the tetragonal I4/mmm space group. Np(1) is bonded in a 20-coordinate geometry to eight equivalent Cr(1), four equivalent Al(1), and eight equivalent Al(2) atoms. Cr(1) is bonded to two equivalent Np(1), two equivalent Cr(1), four equivalent Al(1), and four equivalent Al(2) atoms to form a mixture of distorted face, corner, and edge-sharing CrNp2Al8Cr2 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 10-coordinate geometry to one Np(1), four equivalent Cr(1), one Al(1), and four equivalent Al(2) atoms. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Np(1), four equivalent Cr(1), two equivalent Al(2), and four equivalent Al(1) atoms. is represented by the CIF card [CIF]
data_Np(Al2Cr)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.968
_cell_length_b   6.691
_cell_length_c   6.691
_cell_angle_alpha   97.922
_cell_angle_beta   111.792
_cell_angle_gamma   68.208
_symmetry_Int_Tables_number   1
_cell_volume   191.762
_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
  Np  Np0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.660  0.340  0.660  1.0
  Al  Al2  1  0.340  0.660  0.340  1.0
  Al  Al3  1  0.000  0.340  0.340  1.0
  Al  Al4  1  0.000  0.660  0.660  1.0
  Al  Al5  1  0.717  0.783  0.217  1.0
  Al  Al6  1  0.283  0.217  0.783  1.0
  Al  Al7  1  0.500  0.783  0.783  1.0
  Al  Al8  1  0.500  0.217  0.217  1.0
  Cr  Cr9  1  0.500  0.000  0.500  1.0
  Cr  Cr10  1  0.000  0.000  0.500  1.0
  Cr  Cr11  1  0.500  0.500  0.000  1.0
  Cr  Cr12  1  0.000  0.500  0.000  1.0
[/CIF]
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