The structure described by U4Ni7Si is Hexagonal Laves-derived structured and 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), nine equivalent Ni(1), and three equivalent Si(1) atoms. In the second U site, U(2) is bonded in a 16-coordinate geometry to one U(1), three equivalent U(2), three equivalent Ni(2), and nine equivalent Ni(1) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent U(1), three equivalent U(2), one Ni(2), four equivalent Ni(1), and one Si(1) atom to form NiU6SiNi5 cuboctahedra that share corners with two equivalent Ni(2)U6Ni6 cuboctahedra, corners with two equivalent Si(1)U6Ni6 cuboctahedra, corners with fourteen equivalent Ni(1)U6SiNi5 cuboctahedra, edges with six equivalent Ni(1)U6SiNi5 cuboctahedra, faces with three equivalent Ni(2)U6Ni6 cuboctahedra, faces with three equivalent Si(1)U6Ni6 cuboctahedra, and faces with twelve equivalent Ni(1)U6SiNi5 cuboctahedra. In the second Ni site, Ni(2) is bonded to six equivalent U(2) and six equivalent Ni(1) atoms to form NiU6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)U6SiNi5 cuboctahedra, edges with six equivalent Ni(2)U6Ni6 cuboctahedra, faces with two equivalent Si(1)U6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)U6SiNi5 cuboctahedra. Si(1) is bonded to six equivalent U(1) and six equivalent Ni(1) atoms to form SiU6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)U6SiNi5 cuboctahedra, edges with six equivalent Si(1)U6Ni6 cuboctahedra, faces with two equivalent Ni(2)U6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)U6SiNi5 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_U4SiNi7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.075
_cell_length_b   5.074
_cell_length_c   7.855
_cell_angle_alpha   90.000
_cell_angle_beta   89.989
_cell_angle_gamma   60.004
_symmetry_Int_Tables_number   1
_cell_volume   175.183
_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  0.333  0.082  1.0
  U  U1  1  0.667  0.667  0.918  1.0
  U  U2  1  0.667  0.667  0.563  1.0
  U  U3  1  0.333  0.333  0.437  1.0
  Si  Si4  1  0.000  0.000  0.000  1.0
  Ni  Ni5  1  0.168  0.664  0.754  1.0
  Ni  Ni6  1  0.664  0.168  0.754  1.0
  Ni  Ni7  1  0.168  0.168  0.754  1.0
  Ni  Ni8  1  0.832  0.336  0.246  1.0
  Ni  Ni9  1  0.336  0.832  0.246  1.0
  Ni  Ni10  1  0.832  0.832  0.246  1.0
  Ni  Ni11  1  0.000  0.000  0.500  1.0
[/CIF]
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The structure described by U4Ni7Si is Hexagonal Laves-derived structured and 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), nine equivalent Ni(1), and three equivalent Si(1) atoms. In the second U site, U(2) is bonded in a 16-coordinate geometry to one U(1), three equivalent U(2), three equivalent Ni(2), and nine equivalent Ni(1) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent U(1), three equivalent U(2), one Ni(2), four equivalent Ni(1), and one Si(1) atom to form NiU6SiNi5 cuboctahedra that share corners with two equivalent Ni(2)U6Ni6 cuboctahedra, corners with two equivalent Si(1)U6Ni6 cuboctahedra, corners with fourteen equivalent Ni(1)U6SiNi5 cuboctahedra, edges with six equivalent Ni(1)U6SiNi5 cuboctahedra, faces with three equivalent Ni(2)U6Ni6 cuboctahedra, faces with three equivalent Si(1)U6Ni6 cuboctahedra, and faces with twelve equivalent Ni(1)U6SiNi5 cuboctahedra. In the second Ni site, Ni(2) is bonded to six equivalent U(2) and six equivalent Ni(1) atoms to form NiU6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)U6SiNi5 cuboctahedra, edges with six equivalent Ni(2)U6Ni6 cuboctahedra, faces with two equivalent Si(1)U6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)U6SiNi5 cuboctahedra. Si(1) is bonded to six equivalent U(1) and six equivalent Ni(1) atoms to form SiU6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)U6SiNi5 cuboctahedra, edges with six equivalent Si(1)U6Ni6 cuboctahedra, faces with two equivalent Ni(2)U6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)U6SiNi5 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_U4SiNi7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.075
_cell_length_b   5.074
_cell_length_c   7.855
_cell_angle_alpha   90.000
_cell_angle_beta   89.989
_cell_angle_gamma   60.004
_symmetry_Int_Tables_number   1
_cell_volume   175.183
_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  0.333  0.082  1.0
  U  U1  1  0.667  0.667  0.918  1.0
  U  U2  1  0.667  0.667  0.563  1.0
  U  U3  1  0.333  0.333  0.437  1.0
  Si  Si4  1  0.000  0.000  0.000  1.0
  Ni  Ni5  1  0.168  0.664  0.754  1.0
  Ni  Ni6  1  0.664  0.168  0.754  1.0
  Ni  Ni7  1  0.168  0.168  0.754  1.0
  Ni  Ni8  1  0.832  0.336  0.246  1.0
  Ni  Ni9  1  0.336  0.832  0.246  1.0
  Ni  Ni10  1  0.832  0.832  0.246  1.0
  Ni  Ni11  1  0.000  0.000  0.500  1.0
[/CIF]
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