The material described by U2CuSi3 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Imm2 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent Cu(1), two equivalent Si(3), four equivalent Si(1), and four equivalent Si(2) atoms to form UCu2Si10 cuboctahedra that share edges with four equivalent U(1)Cu2Si10 cuboctahedra, edges with eight equivalent U(2)Cu4Si8 cuboctahedra, faces with four equivalent U(1)Cu2Si10 cuboctahedra, and faces with four equivalent U(2)Cu4Si8 cuboctahedra. In the second U site, U(2) is bonded to four equivalent Cu(1), two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms to form distorted UCu4Si8 cuboctahedra that share edges with four equivalent U(2)Cu4Si8 cuboctahedra, edges with eight equivalent U(1)Cu2Si10 cuboctahedra, faces with four equivalent U(1)Cu2Si10 cuboctahedra, and faces with four equivalent U(2)Cu4Si8 cuboctahedra. Cu(1) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Si(3), and two equivalent Si(2) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), one Si(2), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), two equivalent Cu(1), and one Si(1) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Cu(1), and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_U2CuSi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.472
_cell_length_b   7.472
_cell_length_c   7.472
_cell_angle_alpha   149.307
_cell_angle_beta   148.978
_cell_angle_gamma   44.202
_symmetry_Int_Tables_number   1
_cell_volume   109.425
_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  0.130  0.130  0.000  1.0
  U  U1  1  0.367  0.867  0.500  1.0
  Cu  Cu2  1  0.960  0.460  0.500  1.0
  Si  Si3  1  0.708  0.708  0.000  1.0
  Si  Si4  1  0.538  0.538  0.000  1.0
  Si  Si5  1  0.796  0.296  0.500  1.0
[/CIF]
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The material described by U2CuSi3 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Imm2 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent Cu(1), two equivalent Si(3), four equivalent Si(1), and four equivalent Si(2) atoms to form UCu2Si10 cuboctahedra that share edges with four equivalent U(1)Cu2Si10 cuboctahedra, edges with eight equivalent U(2)Cu4Si8 cuboctahedra, faces with four equivalent U(1)Cu2Si10 cuboctahedra, and faces with four equivalent U(2)Cu4Si8 cuboctahedra. In the second U site, U(2) is bonded to four equivalent Cu(1), two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms to form distorted UCu4Si8 cuboctahedra that share edges with four equivalent U(2)Cu4Si8 cuboctahedra, edges with eight equivalent U(1)Cu2Si10 cuboctahedra, faces with four equivalent U(1)Cu2Si10 cuboctahedra, and faces with four equivalent U(2)Cu4Si8 cuboctahedra. Cu(1) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Si(3), and two equivalent Si(2) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), one Si(2), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), two equivalent Cu(1), and one Si(1) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), one Cu(1), and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_U2CuSi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.472
_cell_length_b   7.472
_cell_length_c   7.472
_cell_angle_alpha   149.307
_cell_angle_beta   148.978
_cell_angle_gamma   44.202
_symmetry_Int_Tables_number   1
_cell_volume   109.425
_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  0.130  0.130  0.000  1.0
  U  U1  1  0.367  0.867  0.500  1.0
  Cu  Cu2  1  0.960  0.460  0.500  1.0
  Si  Si3  1  0.708  0.708  0.000  1.0
  Si  Si4  1  0.538  0.538  0.000  1.0
  Si  Si5  1  0.796  0.296  0.500  1.0
[/CIF]
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