The material described by U2Al3Si crystallizes in the trigonal R-3m space group. U(1) is bonded in a 16-coordinate geometry to four equivalent U(1), nine equivalent Al(1), and three equivalent Si(1) atoms. Al(1) is bonded to six equivalent U(1), four equivalent Al(1), and two equivalent Si(1) atoms to form AlU6Al4Si2 cuboctahedra that share corners with four equivalent Si(1)U6Al6 cuboctahedra, corners with fourteen equivalent Al(1)U6Al4Si2 cuboctahedra, edges with six equivalent Al(1)U6Al4Si2 cuboctahedra, faces with six equivalent Si(1)U6Al6 cuboctahedra, and faces with twelve equivalent Al(1)U6Al4Si2 cuboctahedra. Si(1) is bonded to six equivalent U(1) and six equivalent Al(1) atoms to form SiU6Al6 cuboctahedra that share corners with six equivalent Si(1)U6Al6 cuboctahedra, corners with twelve equivalent Al(1)U6Al4Si2 cuboctahedra, edges with six equivalent Si(1)U6Al6 cuboctahedra, and faces with eighteen equivalent Al(1)U6Al4Si2 cuboctahedra. is represented by the CIF card [CIF]
data_U2Al3Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.386
_cell_length_b   5.386
_cell_length_c   5.386
_cell_angle_alpha   59.695
_cell_angle_beta   59.695
_cell_angle_gamma   59.695
_symmetry_Int_Tables_number   1
_cell_volume   109.714
_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  0.125  0.125  0.125  1.0
  U  U1  1  0.875  0.875  0.875  1.0
  Al  Al2  1  0.500  0.000  0.500  1.0
  Al  Al3  1  0.000  0.500  0.500  1.0
  Al  Al4  1  0.500  0.500  0.000  1.0
  Si  Si5  1  0.500  0.500  0.500  1.0
[/CIF]
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The material described by U2Al3Si crystallizes in the trigonal R-3m space group. U(1) is bonded in a 16-coordinate geometry to four equivalent U(1), nine equivalent Al(1), and three equivalent Si(1) atoms. Al(1) is bonded to six equivalent U(1), four equivalent Al(1), and two equivalent Si(1) atoms to form AlU6Al4Si2 cuboctahedra that share corners with four equivalent Si(1)U6Al6 cuboctahedra, corners with fourteen equivalent Al(1)U6Al4Si2 cuboctahedra, edges with six equivalent Al(1)U6Al4Si2 cuboctahedra, faces with six equivalent Si(1)U6Al6 cuboctahedra, and faces with twelve equivalent Al(1)U6Al4Si2 cuboctahedra. Si(1) is bonded to six equivalent U(1) and six equivalent Al(1) atoms to form SiU6Al6 cuboctahedra that share corners with six equivalent Si(1)U6Al6 cuboctahedra, corners with twelve equivalent Al(1)U6Al4Si2 cuboctahedra, edges with six equivalent Si(1)U6Al6 cuboctahedra, and faces with eighteen equivalent Al(1)U6Al4Si2 cuboctahedra. is represented by the CIF card [CIF]
data_U2Al3Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.386
_cell_length_b   5.386
_cell_length_c   5.386
_cell_angle_alpha   59.695
_cell_angle_beta   59.695
_cell_angle_gamma   59.695
_symmetry_Int_Tables_number   1
_cell_volume   109.714
_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  0.125  0.125  0.125  1.0
  U  U1  1  0.875  0.875  0.875  1.0
  Al  Al2  1  0.500  0.000  0.500  1.0
  Al  Al3  1  0.000  0.500  0.500  1.0
  Al  Al4  1  0.500  0.500  0.000  1.0
  Si  Si5  1  0.500  0.500  0.500  1.0
[/CIF]
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