The structure described by U2NiSi3 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent Ni(1), two equivalent Si(3), four equivalent Si(1), and four equivalent Si(2) atoms to form USi10Ni2 cuboctahedra that share edges with four equivalent U(1)Si10Ni2 cuboctahedra, edges with eight equivalent U(2)Si8Ni4 cuboctahedra, faces with four equivalent U(1)Si10Ni2 cuboctahedra, and faces with four equivalent U(2)Si8Ni4 cuboctahedra. In the second U site, U(2) is bonded to four equivalent Ni(1), two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms to form USi8Ni4 cuboctahedra that share edges with four equivalent U(2)Si8Ni4 cuboctahedra, edges with eight equivalent U(1)Si10Ni2 cuboctahedra, faces with four equivalent U(1)Si10Ni2 cuboctahedra, and faces with four equivalent U(2)Si8Ni4 cuboctahedra. Ni(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 Ni(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 Ni(1), and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_U2Si3Ni
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.853
_cell_length_b   4.005
_cell_length_c   6.853
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   105.728
_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  0.000  0.500  0.999  1.0
  U  U1  1  0.000  0.000  0.501  1.0
  Si  Si2  1  0.500  0.000  0.835  1.0
  Si  Si3  1  0.500  0.000  0.175  1.0
  Si  Si4  1  0.500  0.500  0.659  1.0
  Ni  Ni5  1  0.500  0.500  0.332  1.0
[/CIF]
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The structure described by U2NiSi3 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Pmm2 space group. There are two inequivalent U sites. In the first U site, U(1) is bonded to two equivalent Ni(1), two equivalent Si(3), four equivalent Si(1), and four equivalent Si(2) atoms to form USi10Ni2 cuboctahedra that share edges with four equivalent U(1)Si10Ni2 cuboctahedra, edges with eight equivalent U(2)Si8Ni4 cuboctahedra, faces with four equivalent U(1)Si10Ni2 cuboctahedra, and faces with four equivalent U(2)Si8Ni4 cuboctahedra. In the second U site, U(2) is bonded to four equivalent Ni(1), two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms to form USi8Ni4 cuboctahedra that share edges with four equivalent U(2)Si8Ni4 cuboctahedra, edges with eight equivalent U(1)Si10Ni2 cuboctahedra, faces with four equivalent U(1)Si10Ni2 cuboctahedra, and faces with four equivalent U(2)Si8Ni4 cuboctahedra. Ni(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 Ni(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 Ni(1), and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_U2Si3Ni
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.853
_cell_length_b   4.005
_cell_length_c   6.853
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   105.728
_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  0.000  0.500  0.999  1.0
  U  U1  1  0.000  0.000  0.501  1.0
  Si  Si2  1  0.500  0.000  0.835  1.0
  Si  Si3  1  0.500  0.000  0.175  1.0
  Si  Si4  1  0.500  0.500  0.659  1.0
  Ni  Ni5  1  0.500  0.500  0.332  1.0
[/CIF]
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