The structure described by U2Sm4O11 crystallizes in the monoclinic C2 space group. U(1) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), and two equivalent O(3) atoms. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), two equivalent O(2), and two equivalent O(7) atoms. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(4)Sm2U2 tetrahedra, corners with two equivalent O(6)Sm2U2 tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with six equivalent O(7)Sm3U tetrahedra, edges with two equivalent O(3)Sm2U2 tetrahedra, and edges with two equivalent O(2)Sm3U tetrahedra. In the second O site, O(2) is bonded to one U(1), one Sm(2), and two equivalent Sm(1) atoms to form OSm3U tetrahedra that share  a cornercorner with one O(1)Sm4 tetrahedra, corners with two equivalent O(6)Sm2U2 tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with five equivalent O(3)Sm2U2 tetrahedra,  an edgeedge with one O(4)Sm2U2 tetrahedra,  an edgeedge with one O(1)Sm4 tetrahedra, and edges with three equivalent O(7)Sm3U tetrahedra. In the third O site, O(3) is bonded to two equivalent U(1), one Sm(1), and one Sm(2) atom to form OSm2U2 tetrahedra that share  a cornercorner with one O(4)Sm2U2 tetrahedra, corners with two equivalent O(3)Sm2U2 tetrahedra, corners with three equivalent O(6)Sm2U2 tetrahedra, corners with three equivalent O(7)Sm3U tetrahedra, corners with five equivalent O(2)Sm3U tetrahedra,  an edgeedge with one O(4)Sm2U2 tetrahedra,  an edgeedge with one O(7)Sm3U tetrahedra, and  an edgeedge with one O(1)Sm4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent U(1) and two equivalent Sm(2) atoms to form OSm2U2 tetrahedra that share corners with two equivalent O(3)Sm2U2 tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with four equivalent O(7)Sm3U tetrahedra, edges with two equivalent O(3)Sm2U2 tetrahedra, edges with two equivalent O(6)Sm2U2 tetrahedra, and edges with two equivalent O(2)Sm3U tetrahedra. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one U(1), one Sm(1), and one Sm(2) atom. In the sixth O site, O(6) is bonded to two equivalent U(1) and two equivalent Sm(2) atoms to form OSm2U2 tetrahedra that share corners with two equivalent O(1)Sm4 tetrahedra, corners with four equivalent O(2)Sm3U tetrahedra, corners with six equivalent O(3)Sm2U2 tetrahedra, edges with two equivalent O(4)Sm2U2 tetrahedra, and edges with two equivalent O(7)Sm3U tetrahedra. In the seventh O site, O(7) is bonded to one U(1), one Sm(2), and two equivalent Sm(1) atoms to form OSm3U tetrahedra that share corners with two equivalent O(4)Sm2U2 tetrahedra, corners with two equivalent O(7)Sm3U tetrahedra, corners with three equivalent O(3)Sm2U2 tetrahedra, corners with three equivalent O(1)Sm4 tetrahedra,  an edgeedge with one O(3)Sm2U2 tetrahedra,  an edgeedge with one O(6)Sm2U2 tetrahedra, and edges with three equivalent O(2)Sm3U tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm4U2O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.796
_cell_length_b   6.796
_cell_length_c   7.539
_cell_angle_alpha   73.803
_cell_angle_beta   73.803
_cell_angle_gamma   47.431
_symmetry_Int_Tables_number   1
_cell_volume   244.240
_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
  Sm  Sm0  1  0.960  0.682  0.585  1.0
  Sm  Sm1  1  0.692  0.313  0.760  1.0
  Sm  Sm2  1  0.687  0.308  0.240  1.0
  Sm  Sm3  1  0.318  0.040  0.415  1.0
  U  U4  1  0.026  0.659  0.070  1.0
  U  U5  1  0.341  0.974  0.930  1.0
  O  O6  1  0.920  0.080  0.500  1.0
  O  O7  1  0.765  0.889  0.298  1.0
  O  O8  1  0.708  0.922  0.864  1.0
  O  O9  1  0.956  0.044  0.000  1.0
  O  O10  1  0.238  0.486  0.815  1.0
  O  O11  1  0.425  0.575  0.000  1.0
  O  O12  1  0.577  0.734  0.658  1.0
  O  O13  1  0.514  0.762  0.185  1.0
  O  O14  1  0.266  0.423  0.342  1.0
  O  O15  1  0.111  0.235  0.702  1.0
  O  O16  1  0.078  0.292  0.136  1.0
[/CIF]
.
The structure described by U2Sm4O11 crystallizes in the monoclinic C2 space group. U(1) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), and two equivalent O(3) atoms. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(5), two equivalent O(2), and two equivalent O(7) atoms. In the second Sm site, Sm(2) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form OSm4 tetrahedra that share corners with two equivalent O(4)Sm2U2 tetrahedra, corners with two equivalent O(6)Sm2U2 tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with six equivalent O(7)Sm3U tetrahedra, edges with two equivalent O(3)Sm2U2 tetrahedra, and edges with two equivalent O(2)Sm3U tetrahedra. In the second O site, O(2) is bonded to one U(1), one Sm(2), and two equivalent Sm(1) atoms to form OSm3U tetrahedra that share  a cornercorner with one O(1)Sm4 tetrahedra, corners with two equivalent O(6)Sm2U2 tetrahedra, corners with two equivalent O(2)Sm3U tetrahedra, corners with five equivalent O(3)Sm2U2 tetrahedra,  an edgeedge with one O(4)Sm2U2 tetrahedra,  an edgeedge with one O(1)Sm4 tetrahedra, and edges with three equivalent O(7)Sm3U tetrahedra. In the third O site, O(3) is bonded to two equivalent U(1), one Sm(1), and one Sm(2) atom to form OSm2U2 tetrahedra that share  a cornercorner with one O(4)Sm2U2 tetrahedra, corners with two equivalent O(3)Sm2U2 tetrahedra, corners with three equivalent O(6)Sm2U2 tetrahedra, corners with three equivalent O(7)Sm3U tetrahedra, corners with five equivalent O(2)Sm3U tetrahedra,  an edgeedge with one O(4)Sm2U2 tetrahedra,  an edgeedge with one O(7)Sm3U tetrahedra, and  an edgeedge with one O(1)Sm4 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent U(1) and two equivalent Sm(2) atoms to form OSm2U2 tetrahedra that share corners with two equivalent O(3)Sm2U2 tetrahedra, corners with two equivalent O(1)Sm4 tetrahedra, corners with four equivalent O(7)Sm3U tetrahedra, edges with two equivalent O(3)Sm2U2 tetrahedra, edges with two equivalent O(6)Sm2U2 tetrahedra, and edges with two equivalent O(2)Sm3U tetrahedra. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one U(1), one Sm(1), and one Sm(2) atom. In the sixth O site, O(6) is bonded to two equivalent U(1) and two equivalent Sm(2) atoms to form OSm2U2 tetrahedra that share corners with two equivalent O(1)Sm4 tetrahedra, corners with four equivalent O(2)Sm3U tetrahedra, corners with six equivalent O(3)Sm2U2 tetrahedra, edges with two equivalent O(4)Sm2U2 tetrahedra, and edges with two equivalent O(7)Sm3U tetrahedra. In the seventh O site, O(7) is bonded to one U(1), one Sm(2), and two equivalent Sm(1) atoms to form OSm3U tetrahedra that share corners with two equivalent O(4)Sm2U2 tetrahedra, corners with two equivalent O(7)Sm3U tetrahedra, corners with three equivalent O(3)Sm2U2 tetrahedra, corners with three equivalent O(1)Sm4 tetrahedra,  an edgeedge with one O(3)Sm2U2 tetrahedra,  an edgeedge with one O(6)Sm2U2 tetrahedra, and edges with three equivalent O(2)Sm3U tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm4U2O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.796
_cell_length_b   6.796
_cell_length_c   7.539
_cell_angle_alpha   73.803
_cell_angle_beta   73.803
_cell_angle_gamma   47.431
_symmetry_Int_Tables_number   1
_cell_volume   244.240
_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
  Sm  Sm0  1  0.960  0.682  0.585  1.0
  Sm  Sm1  1  0.692  0.313  0.760  1.0
  Sm  Sm2  1  0.687  0.308  0.240  1.0
  Sm  Sm3  1  0.318  0.040  0.415  1.0
  U  U4  1  0.026  0.659  0.070  1.0
  U  U5  1  0.341  0.974  0.930  1.0
  O  O6  1  0.920  0.080  0.500  1.0
  O  O7  1  0.765  0.889  0.298  1.0
  O  O8  1  0.708  0.922  0.864  1.0
  O  O9  1  0.956  0.044  0.000  1.0
  O  O10  1  0.238  0.486  0.815  1.0
  O  O11  1  0.425  0.575  0.000  1.0
  O  O12  1  0.577  0.734  0.658  1.0
  O  O13  1  0.514  0.762  0.185  1.0
  O  O14  1  0.266  0.423  0.342  1.0
  O  O15  1  0.111  0.235  0.702  1.0
  O  O16  1  0.078  0.292  0.136  1.0
[/CIF]
.