The material structure described by UIr2Si2 crystallizes in the tetragonal P4/nmm space group. U(1) is bonded in a 16-coordinate geometry to four equivalent Ir(1), four equivalent Ir(2), four equivalent Si(1), and four equivalent Si(2) atoms. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a 5-coordinate geometry to four equivalent U(1), one Si(1), and four equivalent Si(2) atoms. In the second Ir site, Ir(2) is bonded to four equivalent U(1) and four equivalent Si(1) atoms to form distorted IrU4Si4 tetrahedra that share corners with twelve equivalent Si(2)U4Ir4 tetrahedra, edges with two equivalent Si(2)U4Ir4 tetrahedra, edges with four equivalent Ir(2)U4Si4 tetrahedra, and faces with four equivalent Ir(2)U4Si4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 5-coordinate geometry to four equivalent U(1), one Ir(1), and four equivalent Ir(2) atoms. In the second Si site, Si(2) is bonded to four equivalent U(1) and four equivalent Ir(1) atoms to form distorted SiU4Ir4 tetrahedra that share corners with twelve equivalent Ir(2)U4Si4 tetrahedra, edges with two equivalent Ir(2)U4Si4 tetrahedra, edges with four equivalent Si(2)U4Ir4 tetrahedra, and faces with four equivalent Si(2)U4Ir4 tetrahedra. is represented by the CIF file [CIF]
data_U(SiIr)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.140
_cell_length_b   4.140
_cell_length_c   9.791
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   167.842
_cell_formula_units_Z   2
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  0.750  0.750  0.256  1.0
  U  U1  1  0.250  0.250  0.744  1.0
  Si  Si2  1  0.750  0.750  0.868  1.0
  Si  Si3  1  0.250  0.250  0.132  1.0
  Si  Si4  1  0.250  0.750  0.500  1.0
  Si  Si5  1  0.750  0.250  0.500  1.0
  Ir  Ir6  1  0.250  0.250  0.373  1.0
  Ir  Ir7  1  0.750  0.750  0.627  1.0
  Ir  Ir8  1  0.250  0.750  0.000  1.0
  Ir  Ir9  1  0.750  0.250  0.000  1.0
[/CIF]
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The material structure described by UIr2Si2 crystallizes in the tetragonal P4/nmm space group. U(1) is bonded in a 16-coordinate geometry to four equivalent Ir(1), four equivalent Ir(2), four equivalent Si(1), and four equivalent Si(2) atoms. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a 5-coordinate geometry to four equivalent U(1), one Si(1), and four equivalent Si(2) atoms. In the second Ir site, Ir(2) is bonded to four equivalent U(1) and four equivalent Si(1) atoms to form distorted IrU4Si4 tetrahedra that share corners with twelve equivalent Si(2)U4Ir4 tetrahedra, edges with two equivalent Si(2)U4Ir4 tetrahedra, edges with four equivalent Ir(2)U4Si4 tetrahedra, and faces with four equivalent Ir(2)U4Si4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 5-coordinate geometry to four equivalent U(1), one Ir(1), and four equivalent Ir(2) atoms. In the second Si site, Si(2) is bonded to four equivalent U(1) and four equivalent Ir(1) atoms to form distorted SiU4Ir4 tetrahedra that share corners with twelve equivalent Ir(2)U4Si4 tetrahedra, edges with two equivalent Ir(2)U4Si4 tetrahedra, edges with four equivalent Si(2)U4Ir4 tetrahedra, and faces with four equivalent Si(2)U4Ir4 tetrahedra. is represented by the CIF file [CIF]
data_U(SiIr)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.140
_cell_length_b   4.140
_cell_length_c   9.791
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   167.842
_cell_formula_units_Z   2
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  0.750  0.750  0.256  1.0
  U  U1  1  0.250  0.250  0.744  1.0
  Si  Si2  1  0.750  0.750  0.868  1.0
  Si  Si3  1  0.250  0.250  0.132  1.0
  Si  Si4  1  0.250  0.750  0.500  1.0
  Si  Si5  1  0.750  0.250  0.500  1.0
  Ir  Ir6  1  0.250  0.250  0.373  1.0
  Ir  Ir7  1  0.750  0.750  0.627  1.0
  Ir  Ir8  1  0.250  0.750  0.000  1.0
  Ir  Ir9  1  0.750  0.250  0.000  1.0
[/CIF]
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