The material described by U3Cu4Si4 crystallizes in the orthorhombic Immm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 14-coordinate geometry to four equivalent Cu(1), four equivalent Cu(2), two equivalent Si(1), and four equivalent Si(2) atoms. In the second U site, U(2) is bonded to four equivalent Cu(2) and eight equivalent Si(1) atoms to form a mixture of face and edge-sharing UCu4Si8 cuboctahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent U(1), four equivalent Cu(1), and four equivalent Si(2) atoms to form a mixture of distorted face and corner-sharing CuU4Cu4Si4 cuboctahedra. In the second Cu site, Cu(2) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), one Si(2), and two equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), two equivalent Cu(2), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent U(1), one Cu(2), and four equivalent Cu(1) atoms. is represented by the CIF card [CIF]
data_U3(CuSi)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.942
_cell_length_b   3.998
_cell_length_c   12.162
_cell_angle_alpha   99.461
_cell_angle_beta   99.326
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   186.475
_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  0.853  0.353  0.706  1.0
  U  U1  1  0.147  0.647  0.294  1.0
  U  U2  1  0.000  0.000  0.000  1.0
  Cu  Cu3  1  0.250  0.250  0.500  1.0
  Cu  Cu4  1  0.750  0.750  0.500  1.0
  Cu  Cu5  1  0.596  0.096  0.193  1.0
  Cu  Cu6  1  0.404  0.904  0.807  1.0
  Si  Si7  1  0.451  0.451  0.901  1.0
  Si  Si8  1  0.549  0.549  0.099  1.0
  Si  Si9  1  0.693  0.193  0.386  1.0
  Si  Si10  1  0.307  0.807  0.614  1.0
[/CIF]
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The material described by U3Cu4Si4 crystallizes in the orthorhombic Immm space group. There are two inequivalent U sites. In the first U site, U(1) is bonded in a 14-coordinate geometry to four equivalent Cu(1), four equivalent Cu(2), two equivalent Si(1), and four equivalent Si(2) atoms. In the second U site, U(2) is bonded to four equivalent Cu(2) and eight equivalent Si(1) atoms to form a mixture of face and edge-sharing UCu4Si8 cuboctahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent U(1), four equivalent Cu(1), and four equivalent Si(2) atoms to form a mixture of distorted face and corner-sharing CuU4Cu4Si4 cuboctahedra. In the second Cu site, Cu(2) is bonded in a 9-coordinate geometry to two equivalent U(2), four equivalent U(1), one Si(2), and two equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent U(1), four equivalent U(2), two equivalent Cu(2), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to four equivalent U(1), one Cu(2), and four equivalent Cu(1) atoms. is represented by the CIF card [CIF]
data_U3(CuSi)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.942
_cell_length_b   3.998
_cell_length_c   12.162
_cell_angle_alpha   99.461
_cell_angle_beta   99.326
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   186.475
_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  0.853  0.353  0.706  1.0
  U  U1  1  0.147  0.647  0.294  1.0
  U  U2  1  0.000  0.000  0.000  1.0
  Cu  Cu3  1  0.250  0.250  0.500  1.0
  Cu  Cu4  1  0.750  0.750  0.500  1.0
  Cu  Cu5  1  0.596  0.096  0.193  1.0
  Cu  Cu6  1  0.404  0.904  0.807  1.0
  Si  Si7  1  0.451  0.451  0.901  1.0
  Si  Si8  1  0.549  0.549  0.099  1.0
  Si  Si9  1  0.693  0.193  0.386  1.0
  Si  Si10  1  0.307  0.807  0.614  1.0
[/CIF]
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