The material structure described by SmIr2Si2 crystallizes in the tetragonal P4/nmm space group. Sm(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 to four equivalent Sm(1) and four equivalent Si(2) atoms to form a mixture of distorted edge and face-sharing IrSm4Si4 tetrahedra. In the second Ir site, Ir(2) is bonded in a 9-coordinate geometry to four equivalent Sm(1), one Si(2), and four equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 4-coordinate geometry to four equivalent Sm(1) and four equivalent Ir(2) atoms. In the second Si site, Si(2) is bonded in a 5-coordinate geometry to four equivalent Sm(1), one Ir(2), and four equivalent Ir(1) atoms. is represented by the CIF file [CIF]
data_Sm(SiIr)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.156
_cell_length_b   4.156
_cell_length_c   9.812
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   169.483
_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
  Sm  Sm0  1  0.750  0.750  0.255  1.0
  Sm  Sm1  1  0.250  0.250  0.745  1.0
  Si  Si2  1  0.750  0.250  0.500  1.0
  Si  Si3  1  0.250  0.750  0.500  1.0
  Si  Si4  1  0.750  0.750  0.870  1.0
  Si  Si5  1  0.250  0.250  0.130  1.0
  Ir  Ir6  1  0.750  0.250  0.000  1.0
  Ir  Ir7  1  0.250  0.750  0.000  1.0
  Ir  Ir8  1  0.750  0.750  0.627  1.0
  Ir  Ir9  1  0.250  0.250  0.373  1.0
[/CIF]
.
The material structure described by SmIr2Si2 crystallizes in the tetragonal P4/nmm space group. Sm(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 to four equivalent Sm(1) and four equivalent Si(2) atoms to form a mixture of distorted edge and face-sharing IrSm4Si4 tetrahedra. In the second Ir site, Ir(2) is bonded in a 9-coordinate geometry to four equivalent Sm(1), one Si(2), and four equivalent Si(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 4-coordinate geometry to four equivalent Sm(1) and four equivalent Ir(2) atoms. In the second Si site, Si(2) is bonded in a 5-coordinate geometry to four equivalent Sm(1), one Ir(2), and four equivalent Ir(1) atoms. is represented by the CIF file [CIF]
data_Sm(SiIr)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.156
_cell_length_b   4.156
_cell_length_c   9.812
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   169.483
_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
  Sm  Sm0  1  0.750  0.750  0.255  1.0
  Sm  Sm1  1  0.250  0.250  0.745  1.0
  Si  Si2  1  0.750  0.250  0.500  1.0
  Si  Si3  1  0.250  0.750  0.500  1.0
  Si  Si4  1  0.750  0.750  0.870  1.0
  Si  Si5  1  0.250  0.250  0.130  1.0
  Ir  Ir6  1  0.750  0.250  0.000  1.0
  Ir  Ir7  1  0.250  0.750  0.000  1.0
  Ir  Ir8  1  0.750  0.750  0.627  1.0
  Ir  Ir9  1  0.250  0.250  0.373  1.0
[/CIF]
.