The crystal structure described by Er2CuSi3 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to four equivalent Cu(1), two equivalent Si(1), two equivalent Si(3), and four equivalent Si(2) atoms to form ErCu4Si8 cuboctahedra that share edges with four equivalent Er(1)Cu4Si8 cuboctahedra, edges with eight equivalent Er(2)Cu2Si10 cuboctahedra, faces with four equivalent Er(2)Cu2Si10 cuboctahedra, and faces with four equivalent Er(1)Cu4Si8 cuboctahedra. In the second Er site, Er(2) is bonded to two equivalent Cu(1), two equivalent Si(2), four equivalent Si(1), and four equivalent Si(3) atoms to form ErCu2Si10 cuboctahedra that share edges with four equivalent Er(2)Cu2Si10 cuboctahedra, edges with eight equivalent Er(1)Cu4Si8 cuboctahedra, faces with four equivalent Er(2)Cu2Si10 cuboctahedra, and faces with four equivalent Er(1)Cu4Si8 cuboctahedra. Cu(1) is bonded in a 9-coordinate geometry to two equivalent Er(2), four equivalent Er(1), one Si(2), and two equivalent Si(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Er(1), four equivalent Er(2), two equivalent Cu(1), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Er(2), four equivalent Er(1), one Cu(1), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Er(1), four equivalent Er(2), one Si(1), and two equivalent Si(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Er2CuSi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.421
_cell_length_b   7.421
_cell_length_c   7.421
_cell_angle_alpha   149.389
_cell_angle_beta   148.473
_cell_angle_gamma   44.517
_symmetry_Int_Tables_number   1
_cell_volume   108.479
_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
  Er  Er0  1  0.754  0.254  0.500  1.0
  Er  Er1  1  0.998  0.998  0.000  1.0
  Cu  Cu2  1  0.163  0.663  0.500  1.0
  Si  Si3  1  0.588  0.588  0.000  1.0
  Si  Si4  1  0.327  0.827  0.500  1.0
  Si  Si5  1  0.420  0.420  0.000  1.0
[/CIF]
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The crystal structure described by Er2CuSi3 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Er sites. In the first Er site, Er(1) is bonded to four equivalent Cu(1), two equivalent Si(1), two equivalent Si(3), and four equivalent Si(2) atoms to form ErCu4Si8 cuboctahedra that share edges with four equivalent Er(1)Cu4Si8 cuboctahedra, edges with eight equivalent Er(2)Cu2Si10 cuboctahedra, faces with four equivalent Er(2)Cu2Si10 cuboctahedra, and faces with four equivalent Er(1)Cu4Si8 cuboctahedra. In the second Er site, Er(2) is bonded to two equivalent Cu(1), two equivalent Si(2), four equivalent Si(1), and four equivalent Si(3) atoms to form ErCu2Si10 cuboctahedra that share edges with four equivalent Er(2)Cu2Si10 cuboctahedra, edges with eight equivalent Er(1)Cu4Si8 cuboctahedra, faces with four equivalent Er(2)Cu2Si10 cuboctahedra, and faces with four equivalent Er(1)Cu4Si8 cuboctahedra. Cu(1) is bonded in a 9-coordinate geometry to two equivalent Er(2), four equivalent Er(1), one Si(2), and two equivalent Si(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Er(1), four equivalent Er(2), two equivalent Cu(1), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Er(2), four equivalent Er(1), one Cu(1), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Er(1), four equivalent Er(2), one Si(1), and two equivalent Si(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Er2CuSi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.421
_cell_length_b   7.421
_cell_length_c   7.421
_cell_angle_alpha   149.389
_cell_angle_beta   148.473
_cell_angle_gamma   44.517
_symmetry_Int_Tables_number   1
_cell_volume   108.479
_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
  Er  Er0  1  0.754  0.254  0.500  1.0
  Er  Er1  1  0.998  0.998  0.000  1.0
  Cu  Cu2  1  0.163  0.663  0.500  1.0
  Si  Si3  1  0.588  0.588  0.000  1.0
  Si  Si4  1  0.327  0.827  0.500  1.0
  Si  Si5  1  0.420  0.420  0.000  1.0
[/CIF]
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