The material structure described by U4Cr7Si crystallizes in the trigonal P-3m1 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), three equivalent Cr(2), and nine equivalent Cr(1) atoms. In the second U site, U(2) is bonded in a 16-coordinate geometry to one U(1), three equivalent U(2), nine equivalent Cr(1), and three equivalent Si(1) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent U(1), three equivalent U(2), one Cr(2), four equivalent Cr(1), and one Si(1) atom to form distorted CrU6Cr5Si cuboctahedra that share corners with two equivalent Cr(2)U6Cr6 cuboctahedra, corners with two equivalent Si(1)U6Cr6 cuboctahedra, corners with fourteen equivalent Cr(1)U6Cr5Si cuboctahedra, edges with six equivalent Cr(1)U6Cr5Si cuboctahedra, faces with three equivalent Cr(2)U6Cr6 cuboctahedra, faces with three equivalent Si(1)U6Cr6 cuboctahedra, and faces with twelve equivalent Cr(1)U6Cr5Si cuboctahedra. In the second Cr site, Cr(2) is bonded to six equivalent U(1) and six equivalent Cr(1) atoms to form CrU6Cr6 cuboctahedra that share corners with twelve equivalent Cr(1)U6Cr5Si cuboctahedra, edges with six equivalent Cr(2)U6Cr6 cuboctahedra, faces with two equivalent Si(1)U6Cr6 cuboctahedra, and faces with eighteen equivalent Cr(1)U6Cr5Si cuboctahedra. Si(1) is bonded to six equivalent U(2) and six equivalent Cr(1) atoms to form SiU6Cr6 cuboctahedra that share corners with twelve equivalent Cr(1)U6Cr5Si cuboctahedra, edges with six equivalent Si(1)U6Cr6 cuboctahedra, faces with two equivalent Cr(2)U6Cr6 cuboctahedra, and faces with eighteen equivalent Cr(1)U6Cr5Si cuboctahedra. is represented by the CIF card [CIF]
data_U4Cr7Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.047
_cell_length_b   5.047
_cell_length_c   8.221
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   181.318
_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
  U  U0  1  0.333  0.667  0.430  1.0
  U  U1  1  0.667  0.333  0.570  1.0
  U  U2  1  0.667  0.333  0.933  1.0
  U  U3  1  0.333  0.667  0.067  1.0
  Cr  Cr4  1  0.831  0.169  0.248  1.0
  Cr  Cr5  1  0.831  0.662  0.248  1.0
  Cr  Cr6  1  0.338  0.169  0.248  1.0
  Cr  Cr7  1  0.169  0.831  0.752  1.0
  Cr  Cr8  1  0.169  0.338  0.752  1.0
  Cr  Cr9  1  0.662  0.831  0.752  1.0
  Cr  Cr10  1  0.000  0.000  0.500  1.0
  Si  Si11  1  0.000  0.000  0.000  1.0
[/CIF]
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The material structure described by U4Cr7Si crystallizes in the trigonal P-3m1 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 16-coordinate geometry to one U(2), three equivalent U(1), three equivalent Cr(2), and nine equivalent Cr(1) atoms. In the second U site, U(2) is bonded in a 16-coordinate geometry to one U(1), three equivalent U(2), nine equivalent Cr(1), and three equivalent Si(1) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent U(1), three equivalent U(2), one Cr(2), four equivalent Cr(1), and one Si(1) atom to form distorted CrU6Cr5Si cuboctahedra that share corners with two equivalent Cr(2)U6Cr6 cuboctahedra, corners with two equivalent Si(1)U6Cr6 cuboctahedra, corners with fourteen equivalent Cr(1)U6Cr5Si cuboctahedra, edges with six equivalent Cr(1)U6Cr5Si cuboctahedra, faces with three equivalent Cr(2)U6Cr6 cuboctahedra, faces with three equivalent Si(1)U6Cr6 cuboctahedra, and faces with twelve equivalent Cr(1)U6Cr5Si cuboctahedra. In the second Cr site, Cr(2) is bonded to six equivalent U(1) and six equivalent Cr(1) atoms to form CrU6Cr6 cuboctahedra that share corners with twelve equivalent Cr(1)U6Cr5Si cuboctahedra, edges with six equivalent Cr(2)U6Cr6 cuboctahedra, faces with two equivalent Si(1)U6Cr6 cuboctahedra, and faces with eighteen equivalent Cr(1)U6Cr5Si cuboctahedra. Si(1) is bonded to six equivalent U(2) and six equivalent Cr(1) atoms to form SiU6Cr6 cuboctahedra that share corners with twelve equivalent Cr(1)U6Cr5Si cuboctahedra, edges with six equivalent Si(1)U6Cr6 cuboctahedra, faces with two equivalent Cr(2)U6Cr6 cuboctahedra, and faces with eighteen equivalent Cr(1)U6Cr5Si cuboctahedra. is represented by the CIF card [CIF]
data_U4Cr7Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.047
_cell_length_b   5.047
_cell_length_c   8.221
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   181.318
_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
  U  U0  1  0.333  0.667  0.430  1.0
  U  U1  1  0.667  0.333  0.570  1.0
  U  U2  1  0.667  0.333  0.933  1.0
  U  U3  1  0.333  0.667  0.067  1.0
  Cr  Cr4  1  0.831  0.169  0.248  1.0
  Cr  Cr5  1  0.831  0.662  0.248  1.0
  Cr  Cr6  1  0.338  0.169  0.248  1.0
  Cr  Cr7  1  0.169  0.831  0.752  1.0
  Cr  Cr8  1  0.169  0.338  0.752  1.0
  Cr  Cr9  1  0.662  0.831  0.752  1.0
  Cr  Cr10  1  0.000  0.000  0.500  1.0
  Si  Si11  1  0.000  0.000  0.000  1.0
[/CIF]
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