The structure described by Eu4OI6 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a distorted single-bond geometry to one O(1), three equivalent I(1), and three equivalent I(2) atoms. In the second Eu site, Eu(2) is bonded in a distorted single-bond geometry to one O(1), three equivalent I(1), and four equivalent I(2) atoms. O(1) is bonded to one Eu(1) and three equivalent Eu(2) atoms to form OEu4 tetrahedra that share corners with six equivalent I(1)Eu4 trigonal pyramids and edges with three equivalent I(1)Eu4 trigonal pyramids. There are two inequivalent I sites. In the first I site, I(1) is bonded to one Eu(1) and three equivalent Eu(2) atoms to form distorted IEu4 trigonal pyramids that share corners with two equivalent O(1)Eu4 tetrahedra, corners with eight equivalent I(1)Eu4 trigonal pyramids, and  an edgeedge with one O(1)Eu4 tetrahedra. In the second I site, I(2) is bonded in a 5-coordinate geometry to one Eu(1) and four equivalent Eu(2) atoms. is represented by the CIF card [CIF]
data_Eu4I6O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.445
_cell_length_b   10.447
_cell_length_c   8.043
_cell_angle_alpha   90.010
_cell_angle_beta   90.010
_cell_angle_gamma   120.007
_symmetry_Int_Tables_number   1
_cell_volume   760.020
_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
  Eu  Eu0  1  0.334  0.667  0.098  1.0
  Eu  Eu1  1  0.667  0.334  0.598  1.0
  Eu  Eu2  1  0.206  0.794  0.487  1.0
  Eu  Eu3  1  0.587  0.793  0.487  1.0
  Eu  Eu4  1  0.207  0.413  0.486  1.0
  Eu  Eu5  1  0.793  0.206  0.987  1.0
  Eu  Eu6  1  0.413  0.206  0.987  1.0
  Eu  Eu7  1  0.793  0.587  0.986  1.0
  I  I8  1  0.135  0.865  0.110  1.0
  I  I9  1  0.729  0.865  0.110  1.0
  I  I10  1  0.135  0.271  0.110  1.0
  I  I11  1  0.865  0.135  0.610  1.0
  I  I12  1  0.271  0.135  0.610  1.0
  I  I13  1  0.865  0.729  0.610  1.0
  I  I14  1  0.465  0.535  0.793  1.0
  I  I15  1  0.071  0.535  0.793  1.0
  I  I16  1  0.465  0.929  0.793  1.0
  I  I17  1  0.535  0.465  0.293  1.0
  I  I18  1  0.929  0.465  0.293  1.0
  I  I19  1  0.535  0.070  0.293  1.0
  O  O20  1  0.333  0.667  0.393  1.0
  O  O21  1  0.667  0.333  0.893  1.0
[/CIF]
.
The structure described by Eu4OI6 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a distorted single-bond geometry to one O(1), three equivalent I(1), and three equivalent I(2) atoms. In the second Eu site, Eu(2) is bonded in a distorted single-bond geometry to one O(1), three equivalent I(1), and four equivalent I(2) atoms. O(1) is bonded to one Eu(1) and three equivalent Eu(2) atoms to form OEu4 tetrahedra that share corners with six equivalent I(1)Eu4 trigonal pyramids and edges with three equivalent I(1)Eu4 trigonal pyramids. There are two inequivalent I sites. In the first I site, I(1) is bonded to one Eu(1) and three equivalent Eu(2) atoms to form distorted IEu4 trigonal pyramids that share corners with two equivalent O(1)Eu4 tetrahedra, corners with eight equivalent I(1)Eu4 trigonal pyramids, and  an edgeedge with one O(1)Eu4 tetrahedra. In the second I site, I(2) is bonded in a 5-coordinate geometry to one Eu(1) and four equivalent Eu(2) atoms. is represented by the CIF card [CIF]
data_Eu4I6O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.445
_cell_length_b   10.447
_cell_length_c   8.043
_cell_angle_alpha   90.010
_cell_angle_beta   90.010
_cell_angle_gamma   120.007
_symmetry_Int_Tables_number   1
_cell_volume   760.020
_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
  Eu  Eu0  1  0.334  0.667  0.098  1.0
  Eu  Eu1  1  0.667  0.334  0.598  1.0
  Eu  Eu2  1  0.206  0.794  0.487  1.0
  Eu  Eu3  1  0.587  0.793  0.487  1.0
  Eu  Eu4  1  0.207  0.413  0.486  1.0
  Eu  Eu5  1  0.793  0.206  0.987  1.0
  Eu  Eu6  1  0.413  0.206  0.987  1.0
  Eu  Eu7  1  0.793  0.587  0.986  1.0
  I  I8  1  0.135  0.865  0.110  1.0
  I  I9  1  0.729  0.865  0.110  1.0
  I  I10  1  0.135  0.271  0.110  1.0
  I  I11  1  0.865  0.135  0.610  1.0
  I  I12  1  0.271  0.135  0.610  1.0
  I  I13  1  0.865  0.729  0.610  1.0
  I  I14  1  0.465  0.535  0.793  1.0
  I  I15  1  0.071  0.535  0.793  1.0
  I  I16  1  0.465  0.929  0.793  1.0
  I  I17  1  0.535  0.465  0.293  1.0
  I  I18  1  0.929  0.465  0.293  1.0
  I  I19  1  0.535  0.070  0.293  1.0
  O  O20  1  0.333  0.667  0.393  1.0
  O  O21  1  0.667  0.333  0.893  1.0
[/CIF]
.